CN1690783A - Liquid crystal display device and method for producing the same - Google Patents

Abstract

A liquid crystal display device 700 includes a pair of substrates, a vertical alignment type liquid crystal layer 490 provided between the pair of substrates, and electrodes 481 and 485 for applying a voltage to the vertical alignment type liquid crystal layer 490 . At least one of the pair of substrates has a rugged structure on a surface which is in contact with the vertical alignment type liquid crystal layer. The surface having the rugged structure formed thereon has a region in which the height of the rugged structure varies along a first direction with a first period and varies along a second direction perpendicular to the first direction with a second period different from the first period. The first period is no less than 0.1 mum and no more than 10 mum, and the second period is no less than 0.1 mum and no more than 10 mum. The vertical alignment type liquid crystal layer 490 has a pretilt due to the rugged structure with no voltage applied thereacross.

Description

Liquid crystal display device and manufacture method thereof

Technical field

The present invention relates to a kind of liquid crystal display device and manufacture method thereof.

Background technology

Liquid crystal display device (LCD) is widely used as the display device of computing machine or televisor.Up to the present, horizontal alignment type LCD is generally popular.Horizontal alignment type LCD uses the liquid crystal display pattern operation of positive nematic liquid crystal with for example TN (twisted-nematic) pattern or STN (supertwist is to row) pattern.

Recently, for viewing angle characteristic and the demonstration contrast that improvement is provided, use the vertical orientating type LCD of VAN (vertical orientated) pattern to drop into actual use to row.Vertical orientating type LCD is a kind of like this LCD, and promptly it shows with normal black (NB) pattern by the vertical alignment-type liquid crystal layer that use is arranged between the pair of electrodes.

In order to improve the demonstration contrast of vertical orientating type LCD, press for the orientation of control vertical alignment-type liquid crystal layer, so that it becomes more even.

A method that obtains aligned liquid crystal layer control is a kind of like this method, and promptly it guarantees that liquid crystal layer has a pre-dumping when not striding across liquid crystal layer and apply voltage.For example, in TN type liquid crystal display device (it is the liquid crystal display device of horizontal alignment type), the orientation of liquid crystal control is controlled the pre-dumping (or more particularly, tilt angle and pre-dumping direction) of liquid crystal molecule and is obtained by using through the horizontal alignment film of friction treatment traditionally.Tilt angle is by the decisions such as material of liquid crystal layer and alignment films, and the pre-dumping direction is determined by frictional direction.In this liquid crystal display device, when not applying voltage, liquid crystal molecule on the alignment layer surface on the liquid crystal layer (liquid crystal director (director)) is not to be parallel to substrate fully, but (" pre-dumping direction ") inclination about 1 ° to 6 ° (" tilt angle ") in a predetermined direction.Therefore, apply voltage in case stride across liquid crystal layer, liquid crystal molecule is just attempted to hold up on the pre-dumping direction, thereby causes the even and mild variation in the optic response.

Yet, in the situation of vertical alignment-type liquid crystal display device, the pre-dumping direction of liquid crystal layer even can not be by to carrying out friction treatment and control with being stabilized for the vertical alignment layer that provides of control is provided.And, because the vertical alignment-type liquid crystal display device has than the higher contrast of horizontal alignment type liquid crystal display device, thus in orientation in addition slight unevenness can both be in sight, therefore cause showing inhomogeneous.

Therefore, after deliberation be orientated the whole bag of tricks of control for the vertical alignment-type liquid crystal display device.For example, the method (" fringing field (fringe field) technology ") that has proposed that the method (" rib (rib) technology ") of projection is set and otch is set in pixel electrode in pixel.According to these methods, needn't carry out friction treatment to alignment films and just can limit liquid crystal aligning by rib structure or fringing field (that is tilting electric field).

By using rib technology or fringing field technology, not only can realize than orientation control more stable in the friction treatment situation, but also have an advantage, promptly make orientation cut apart relatively easy (MVA pattern; Multi-domain vertical alignment).In the MVA pattern, a plurality of zones (" farmland ") that allow to have different orientation direction (for example pre-dumping direction) are present in each pixel, guarantee that simultaneously the area on these farmlands is balanced.Therefore, can reduce to improve viewing angle characteristic greatly thus owing to changing the brightness that direction of observation causes or the acute variation of contrast.

As realizing that orientation cuts apart the simplest method, disclose and a kind of a pixel has been divided into the method for four parts, (for example, Jap.P. No.2947350) as shown in fig. 1.Afterwards, will describe orientation as an example by the method shown in Fig. 1 cuts apart.

Do not applying under the voltage condition, as shown in Fig. 2 A, in each of four cut zone (" farmland "), be positioned at along the liquid crystal molecule on the mid-plane of liquid crystal layer direction 12 (being called " central element " afterwards) is formed with the direction on surface of each substrate 11 of vertical alignment layer thereon in approximate vertical on and be orientated.If a pair of polarizer 11 so is set, promptly their axis of homology is perpendicular to one another (quadrature Niccol (cross Nicol)), and liquid crystal layer is clipped between them, and light just can transmission not pass through liquid crystal layer, therefore produces " black " show state.

Next, when striding across liquid crystal layer and apply voltage, shown in Fig. 2 B, central element 12 drops on the direction by rib or fringing field restriction.As a result, because its birefringence, liquid crystal layer is passed through in the present transmission of light.If being orientated as shown in Figure 1, each pixel cuts apart, the direction that central element 12 falls in each farmland (by arrow 13 expressions) is different between farmland and farmland, although the viewing angle characteristic less than the best on each farmland, as long as the area on four farmlands must be balanced, then just can obtain outstanding viewing angle characteristic.

Do not realize that above-mentioned orientation cuts apart if rib and otch are not set in each pixel, then must formation for example can in single pixel, produce a plurality of vertical alignment layers with farmland of different pre-dumping directions.Yet according to any routine techniques that uses friction treatment, friction has to carry out repeatedly (for example four times) on different directions, and is each for different farmlands.Because rub, so the accuracy of separation, makes the practical application difficulty thus with variation with cloth.

On the other hand, rib technology and fringing field technology also have a problem,, because rib and otch are arranged in each pixel, so aperture opening ratio descends, cause dark demonstration thus that is.As used herein, aperture opening ratio is the area ratio that pixel allows part that transmittance passes through and this pixel.In addition, it is complicated that the structure of elements such as substrate, electrode becomes, so productive rate is lower, and owing to be included in the increase of the step number in the production process, production cost increases.

Therefore, a current method of just studying is, do not use friction treatment and form vertical alignment layer with predetermined surface structure, and the pre-dumping direction of the surface structure control vertical alignment-type liquid crystal layer by utilizing this vertical alignment layer.At following two kinds of methods a lot of proposals have been arranged, a kind of method is the method that forms the periodic undulations (concavo-convex (ruggedness)) with fine pitch on the surface of each vertical alignment layer, another kind method is on the basilar memebrane with predetermined surface structure vertical alignment layer to be set, to control the surface structure of each vertical alignment layer.

For example, proposed a kind of method, wherein vertical alignment layer has been coated to its surface and goes up to be formed with on the substrate of SiO film and (for example see T.UCHIDA by the inclination evaporation, M.OHGAWARA, M.WADA, Jpn.J.Appl.Phys., 19, pp2127-2136 (1980)).The SiO film that obtains by the inclination evaporation has the surface structure that is arranged as feature with small column (column) (element characteristic (unit feature)).According to the method for UCHIDA etc., construct by the surface of SiO film and to control the pre-dumping direction.UCHIDA etc. have also described to construct by the surface that changes evaporation condition adjustment SiO film and have controlled tilt angle.

In the open No.3-150530 of Japanese laid-open patent, a kind of method has been proposed, its glass substrate or surperficial vapour deposition that tilts that has the groove of diffraction grating shape by use has the substrate of SiO to impress on the surface of vertical alignment layer as pressing mold.

The method that proposes among the open No.3-150530 of the method for propositions such as front UCHIDA and Japanese laid-open patent all relates to generation for example to be had the structure of the substrate of predetermined surface structure or pressing mold and forms the vertical alignment layer that its surface structure has reflected the surface structure of this structure.Yet because utilize the inclination evaporation to produce this structure, so these methods have following problems.

The first, construct very difficult in the surface of control structure accurately with the inclination evaporation.This problem forms in the have fine pitch situation of element characteristic of (for example a few μ m or littler) especially outstanding on vertical alignment layer.The second, can not at random stipulate the structure (angle of groove dip plane, orientation etc. in other words) of each element characteristic of this structure.Because the structure of the element characteristic that forms on SiO film surface by the inclination evaporation depends on the evaporation condition, so limited the structure of selectable element characteristic.Therefore, be difficult to obtain to have the pre-dumping of any direction or angle, thereby, limited the application of display device.The 3rd, in be orientated the situation of cutting apart in order to improve viewing angle characteristic (MVA pattern), must form and allow at a pixel internal storage at a plurality of vertical alignment layers with zone (farmland) of different pre-dumping directions.Yet using the inclination evaporation to produce the structure that is used to form vertical alignment layer will make manufacturing process become complicated.In addition, drop in the predetermined scope, utilize any method of inclination evaporation must guarantee that all specific or bigger distance is arranged between evaporation source and the substrate surface in order to ensure incident angle with respect to substrate surface.Therefore need huge equipment, thereby make that making large display device becomes difficult.

On the other hand, at M Y.KAWAI, I.IRIE, T.SHIMAMURA, T.KAGASHIRO, H.OKADA, and H.ONNAGAWA, in " Control of nematic liquid crystalalignment using an ultra-fine periodical structures (using superfine periodic structure control nematic liquid crystal orientation) " (the Preprint 111-112 pages or leaves of 2002 liquid crystal symposium (liquid crystal discussion)), a kind of method has been proposed, its by utilize to interfere exposure on substrate surface, form by meticulous groove periodically forms concavo-convex, thereby the generation liquid crystal is vertical orientated.

Yet KAWAI etc. do not mention fully and make vertical orientated liquid crystal molecule pre-dumping.In addition, be by allowing to exist the sinusoidal interference striped of square crossing to obtain at descriptions such as KAWAI concavo-convex, therefore, to the structure of optional fine groove be arranged with restriction.In addition, because form similar feature, so be difficult to separately control along the feature of y direction with along the feature of x direction along two directions that are perpendicular to one another (x direction, y direction).Therefore, when this method being applied to the display device of MVA pattern for example, may make manufacturing process's complexity.

As mentioned above, in order to carry out the orientation control of vertical alignment-type liquid crystal layer, although proposed with surface that liquid crystal layer contacts on the method for small fluctuating (concavo-convex) is set, but do not reducing aperture opening ratio or do not making under manufacturing process's complicated situation, it is difficult to obtain to any of liquid crystal aligning and strictness control.

Summary of the invention

In order to overcome the problems referred to above, made the present invention, primary and foremost purpose is to be formed on the lip-deep small concaveconvex structure (concavo-convex) that contacts with liquid crystal layer by use, gives the vertical alignment-type liquid crystal layer with pre-dumping, comes pinpoint accuracy ground control liquid crystal aligning.

Liquid crystal display device of the present invention is following a kind of liquid crystal display device, the electrode that it comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein, at least one in the described a pair of substrate with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure; The height that the described surface that is formed with concaveconvex structure thereon has a wherein said concaveconvex structure along first direction with the period 1 change, and along zone that the second direction perpendicular to described first direction changed with the second round that is different from the period 1; Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m; And because described concaveconvex structure, when not applying voltage, the vertical alignment-type liquid crystal layer has a pre-dumping.

In a preferred embodiment, when not applying voltage, the normal direction that is positioned at along the orientation of the liquid crystal molecule of the mid-plane (middle level) of described vertical alignment-type liquid crystal layer thickness direction from described a pair of substrate tilts.

In a preferred embodiment, the described period 1 is less than described second round.

Preferably, the height of described concaveconvex structure is equal to or greater than 0.2 times of described period 1.More preferably, the height of wherein said concaveconvex structure is equal to or greater than 0.5 times of described period 1.

In a preferred embodiment, described concaveconvex structure comprises a plurality of element characteristics of arranging with two-dimensional array, and each element characteristic all has asymmetric xsect along described first direction.

Each element characteristic all has the xsect of general triangular along described first direction.

Each element characteristic all has roughly tetragonal xsect along described first direction.

Each element characteristic all has roughly trapezoidal xsect along described first direction.

A base angle of the roughly trapezoidal xsect of each element characteristic is equal to or greater than 90 ° and less than 180 °.

Described element characteristic is arranged with interval along first direction.

Described concaveconvex structure comprises a plurality of grooves of arranging on second direction.

Each groove part extends along described first direction.

Each groove all has roughly quadrilateral and symmetrical xsect along described second direction.

In a preferred embodiment, each groove part has the width that is not less than 0.1 μ m and is not more than 10 μ m.

In a preferred embodiment, described concaveconvex structure comprises capable A and row B, each row A has the element characteristic of arranging on described first direction, each row B is identical with row A and moved less than the element characteristic distance of average period along described first direction; And row A and row B replace on described second direction.

The another kind of liquid crystal display device of the present invention is following a kind of liquid crystal display device, the electrode that it comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein, at least one in the described a pair of substrate with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure; The height that the described surface that is formed with concaveconvex structure thereon has a wherein said concaveconvex structure along first direction change with the period 1 and along perpendicular to the second direction of described first direction to equal or to be different from the zone that changes the second round of period 1; Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m; Described concaveconvex structure comprises a plurality of grooves, and each groove part has the xsect of quadrilateral roughly and symmetry, and each groove part extends being different from the direction of described second direction; And because described concaveconvex structure, when not applying voltage, the vertical alignment-type liquid crystal layer has a pre-dumping.

The another kind of liquid crystal display device of the present invention is following a kind of liquid crystal display device, the electrode that it comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein, at least one in the described a pair of substrate with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure; Described concaveconvex structure comprises capable A and row B, each row A has the element characteristic of arranging with the period 1 along first direction, each row B is identical with row A and moved less than the element characteristic distance of average period along described first direction, row A and row B on perpendicular to the second direction of described first direction with the second round that equals or be different from the described period 1 alternately; Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m; And because described concaveconvex structure, when not applying voltage, the vertical alignment-type liquid crystal layer has a pre-dumping.

The another kind of liquid crystal display device of the present invention is following a kind of liquid crystal display device, the electrode that it comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein, at least one in the described a pair of substrate with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure; Described concaveconvex structure comprise a plurality of along first direction to be not less than 0.1 μ m and to be not more than the element characteristic of the periodic arrangement of 10 μ m, each element characteristic all has the roughly shape of cylindricality; Each bottom surface by those the most adjacent in these a plurality of element characteristics encirclements does not all have rotation axes of symmetry on the substrate normal direction; And because described concaveconvex structure, the vertical alignment-type liquid crystal layer when not applying voltage has a pre-dumping.

In a preferred embodiment, when not striding across described vertical alignment-type liquid crystal layer and apply voltage, the normal direction that is positioned at along the orientation of the liquid crystal molecule of the mid-plane of described vertical alignment-type liquid crystal layer thickness direction from described a pair of substrate tilts.

Preferably, described a plurality of element characteristic has the height that is not less than 0.1 μ m and is not more than 3 μ m.

Each element characteristic all is a triangular prism.

Each element characteristic all is five jiaos of prisms.

In a preferred embodiment, each element characteristic all has the shape of determining according to the certain position (position) of this element characteristic on substrate.

In a preferred embodiment, described concaveconvex structure has been formed a plurality of subregions that cause different pre-dumping directions respectively.

The concaveconvex structure of a plurality of subregions of described composition can all be set on two substrates of described a pair of substrate so that each subregion on of described a pair of substrate all with another substrate on corresponding subregion relative with man-to-man relation.

The concaveconvex structure of a plurality of subregions of described composition can all be set, so that each subregion on of described a pair of substrate is all relative with corresponding a plurality of subregions on another substrate on two substrates of described a pair of substrate.

The concaveconvex structure of a plurality of subregions of described composition can only be set on of described a pair of substrate.

In a preferred embodiment, described liquid crystal display device further comprises a plurality of pixels with arranged, and wherein, in the zone corresponding to each pixel, described concaveconvex structure has been formed one group of subregion that causes different pre-dumping directions respectively.

In a preferred embodiment, described liquid crystal display device further comprises a plurality of pixels with arranged, wherein, in zone corresponding to each pixel, described concaveconvex structure has been formed the many groups subregion that causes different pre-dumping directions respectively, and described many group subregions are arranged in has spacing GP.

Each pixel all comprises the opening that allows the essentially rectangular that transmittance passes through, and described opening has along the long limit that the column direction of described picture element matrix extends with along the minor face of the line direction extension of described picture element matrix; And described concaveconvex structure can be divided into bar, thereby forms described a plurality of subregion, and each subregion all extends on the long limit that both is not parallel to described opening also is not parallel to the direction of its minor face.

The long edge lengths H of each opening _pBe substantially equal to bond length W _pIntegral multiple; Bond length W _pBe substantially equal to the integral multiple of the spacing GP of described many group subregions; And described subregion extends on the direction with respect to the about angle at 45 of described opening minor face.

In a preferred embodiment, each subregion all comprises a plurality of tiny areas that cause different tilt angles respectively.

In a preferred embodiment, described concaveconvex structure has (embossed) surface that is stamped.

The method of making described liquid crystal display device according to the present invention comprises the steps: to prepare the substrate that is formed with concaveconvex structure on its surface; And between described substrate and another substrate relative, the vertical alignment-type liquid crystal layer is set with described substrate.

In a preferred embodiment, the preparation step of substrate that is formed with concaveconvex structure in its surface comprises the steps: to prepare the mother matrix (master) that has corresponding to the surface structure of described concaveconvex structure; Impress (perhaps transfer printing) to the surface of described substrate with surface structure with described mother matrix.

According to the present invention, be formed on the lip-deep small concaveconvex structure that contacts with liquid crystal layer by use, can give the roughly pre-dumping uniformly of liquid crystal molecule that is positioned at along the mid-plane of vertical alignment-type liquid crystal layer thickness direction.Thus, can control liquid crystal aligning accurately, thereby obtain the demonstration of high-contrast.Because by the orientation of plane (two dimension) adjustment liquid crystal layer, so can improve response characteristic.In addition, shape that can be by the control concaveconvex structure and/or arrange realizes that orientation cuts apart, and can improve viewing angle characteristic.

Further feature of the present invention, element, operation, step, characteristic and advantage will become more apparent from detailed description of preferred embodiments of the invention with reference to the accompanying drawings.

Description of drawings

Fig. 1 is the figure that explains that orientation is cut apart.

Fig. 2 A and 2B are the figure that explains the VAN pattern.

Fig. 3 A and 3B are the schematic diagrams of explaining based on the orientation control of concaveconvex structure.

Fig. 4 is the figure that shows the liquid crystal aligning analog result.

The figure that concerns between Fig. 5 element characteristic shape that to be explanation obtain from simulation and the inclination angle.

Fig. 6 A and 6B are the figure that explains the orientation control of parallel alignment type liquid crystal layer.

Fig. 7 A is the figure that is presented at the analog result of liquid crystal aligning in the situation of not introducing disclination (disclination).Fig. 7 B is the figure that is presented at the analog result of liquid crystal aligning in the situation of introducing disclination.

Fig. 8 A and 8B are the skeleton view and the cross-sectional views of display orientation control element example structure respectively.Fig. 8 C and 8D are the skeleton view and the cross-sectional views of another example structure of display orientation control element respectively.

Fig. 9 A and 9B are planimetric map and the cross-sectional views that is presented at the orientation control element surface liquid crystal molecular orientation shown in Fig. 8 C and the 8D respectively.

Figure 10 A and 10B are the schematic cross section of explanation liquid crystal display device example structure of the present invention.

Figure 11 A and 11B are the schematic cross section of the liquid crystal display device example structure of explanation embodiment 1.

Figure 12 A and 12B are the skeleton view of explanation according to the orientation control element example structure of embodiment of the present invention 1.

Figure 13 A is the figure of explanation according to the parameter of the orientation control structure of embodiment of the present invention 1 to 13C.

Figure 14 A and 14B are the figure that explains the definition at inclination angle and pre-dumping among the present invention.

Figure 15 A and 15B are the figure that explains the graphic method that utilizes the two-beam interference exposure.

Figure 16 A each in the 16D all is the skeleton view of explanation according to the orientation control element example structure of embodiment of the present invention 2.

Figure 17 A and 17B are the figure that explains unit area and subregion in the orientation control element.

Figure 18 A and 18B are the skeleton views that shows according to the subregion structure of embodiment of the present invention 3.

Figure 19 A each in the 19C all is the figure that explanation is divided into unit area the illustrative methods of subregion.

Figure 20 A and 20B are the figure of explanation according to the summary of the reproduction technology of embodiment of the present invention 4.

Figure 21 A is the cross-sectional view of explaining according to the step in the method for the formation orientation control element of embodiment of the present invention 4 to 21D.

Figure 22 is the schematic representation of apparatus that is used in according in the imprint step of embodiment of the present invention 4.

Figure 23 is another schematic representation of apparatus that is used in according in the imprint step of embodiment of the present invention 4.

Figure 24 is a schematic representation of apparatus again that is used in according in the imprint step of embodiment of the present invention 4.

Figure 25 is the another schematic representation of apparatus that is used in according in the imprint step of embodiment of the present invention 4.

Figure 26 A each in the 26C all is the figure of the example division pattern of explanation unit area.

Figure 27 A and 27B are planimetric map and the skeleton views that is presented at pixel structure in the active-matrix liquid crystal display device respectively.

Figure 28 is that explanation is at the planimetric map according to the structure of the exemplary pixels in the liquid crystal display device of embodiment of the present invention 5.

Figure 29 is the curve map that shows light transmission Tr when striding across liquid crystal layer and apply voltage V.

Among Figure 30 A and the 30B each all is the skeleton view of explanation according to the exemplary subregion structure of embodiment of the present invention 6.

Figure 31 A is the figure of explanation according to the exemplary unit area structure of embodiment of the present invention 6.Figure 31 B and 31C are the figure of transmissivity measurement result in the tiny area that illustrates in the unit area that is included in Figure 31 A.

Figure 32 A and 32B are cross-sectional view and the planimetric maps that shows respectively according to the orientation control element structure of embodiment of the present invention 7.

Figure 33 A is the spacing of explaining according to the element characteristic of embodiment of the present invention 7 to 33E, and the figure of the angle of dip plane or side.

Figure 34 A is to explain the schematic cross section of manufacturing according to the method for the orientation control element of embodiment of the present invention 7 to 34E.

Figure 35 A is to explain the schematic cross section of manufacturing according to the other method of the orientation control element of embodiment of the present invention 7 to 35E.

Figure 36 A is to explain the schematic cross section of making according to the orientation control element of embodiment of the present invention 7 of a method again to 36D.

Figure 37 A is the figure that explains according to the orientation control element structure of embodiment of the present invention 8 to 37C.

Embodiment

Afterwards, the preferred embodiment of the invention is described with reference to the accompanying drawings.

According to the present invention, small concaveconvex structure (or small concavo-convex) is introduced in the surface that contacts with liquid crystal layer, and it is vertical orientated that described concaveconvex structure is in liquid crystal layer.In this manual, this concaveconvex structure can be called " orientation control structure ".

At first, will principle that control orientation by the surface that concavo-convex introducing is contacted with liquid crystal layer be described.With reference to the skeleton view of Fig. 3 A and the cross-sectional view of Fig. 3 B, an example will be described, wherein liquid crystal molecule 17 is orientated by the substrate 15 that its surface is provided with a plurality of element characteristics 16.

Each element characteristic 16 all is made of two faces (face A, face B) that tilt in different directions, and the shape of cross section with general triangular.On the surface of element characteristic 16, form the vertical alignment layer (not shown).Described vertical alignment layer has the surface of the surface structure of reflection element characteristic 16.When liquid crystal layer being set contacting with this vertical alignment layer, the liquid crystal molecule 17 in the liquid crystal layer is oriented orthogonal to the surface of described vertical alignment layer.In other words, any liquid crystal molecule that is positioned on the face B of element characteristic 16 all is oriented perpendicularly to face B, and any liquid crystal molecule that is positioned on the face A all is oriented perpendicularly to face A.Therefore, by concavo-convex, just can control the vergence direction and the angle of liquid crystal molecule in the vertical alignment-type liquid crystal layer to the surface introducing that contacts with liquid crystal layer.

Note, be used to realize that (undulation-based) technology based on rising and falling of parallel alignment type liquid crystal layer orientation is known,, disclose this technology among the Mol.Cryst.Liq.Cryst.Suppl.1 (1987) 1 for example at J.COGNARD.In parallel-oriented situation, as shown in Figure 6A and 6B, face A and face B can be used for controlling the azimuth direction of liquid crystal molecule; Yet the face of these inclinations can not be used for freely controlling the pre-dumping of initial orientation.Therefore, should be appreciated that the orientation control technology of the vertical alignment-type liquid crystal layer that the known technology that is used for parallel alignment type liquid crystal layer orientation control and use aforesaid and described below are concavo-convex is completely different.

When being applied to the liquid crystal display device of VAN pattern based on the orientation control that rises and falls, following problem can take place.

Get back to Fig. 3 A and 3B, suppose that element characteristic 16 has approximately and identical cycle (spacing) P of pel spacing (for example 100 μ m), if made each pixel portion only determine by coverage at face A, then can only realize the orientation of liquid crystal molecule 17 by face B by the zone corresponding in the structure of whole surface with face B.Therefore in other words, liquid crystal molecule 17 is orientated on the normal direction of face B, with respect to the normal slope of substrate 15.Yet, all have in the general liquid crystal display device of size of wide 100 μ m, thick 3 to 5 μ m in each pixel, in order to obtain good orientation control, must guarantee liquid crystal molecule 17 about 3 ° from the substrate normal slope to liquid crystal layer.If provide such inclination angle by the element characteristic 16 of aforementioned dimensions, then the ridge of element characteristic 16 (ridge) will have to raise, so that surpass the thickness of liquid crystal layer.Forming such element characteristic 16 in the unit is impossible physically.

On the other hand, if the ratio pel spacing that the repetition period P of element characteristic 16 does is little, then can in a pixel, form a plurality of element characteristics 16.As a result, will there be different orientations, promptly owing to the orientation of face A with owing to the orientation of face B.Although can block surface A so that only realize orientation, can reduce in the sort of situation split shed rate by face B, therefore cause showing slinkingly show and make must adjustment face A and face B between area ratio.

Yet, even the area ratio between face A and the face B is optimized, so that can realize the orientation of liquid crystal molecule 17 is controlled, will cause effective element thickness fluctuation but be introduced in contact with liquid crystal layer lip-deep concavo-convex.Therefore, have Luminance Distribution in each pixel, this can cause transmissivity to reduce.In order to stop this fluctuation of effective element thickness, must further reduce the repetition period P (for example being reduced to 10 μ m or littler) of element characteristic 16.

On the other hand, if repetition period P is 1 μ m or littler, then be orientated the diffraction grating that control element 15 will serve as visible light, thereby when it is applied to liquid crystal display device, can cause the painted of pixel.Therefore, in order to realize satisfied demonstration, wish that cycle P is not less than 1 μ m.

Yet, to be orientated the introducing liquid crystal layer if having about 1 μ m to the orientation control element 15 of the small element characteristic 16 of the repetition period P of about 10 μ m by use, then can be because of cancelling each other out and the generation problem owing to the orientation of face A with owing to the orientation of face B, thus make that giving sufficient pre-dumping for liquid crystal layer inside becomes difficult.

By using, can check the orientation of liquid crystal molecule in the liquid crystal layer wherein with the substrate 15 of 10 μ m repetition period P arrangement units features 16.Fig. 4 shows this Simulation result.Be used in the thickness that liquid crystal layer in this simulation has 20 μ m.

As can be seen from Figure 4, between liquid crystal layer and each element characteristic 16 orientation of the liquid crystal molecule 17 at interphase place (being called " interface liquid crystal molecule " afterwards) by the dip plane A of element characteristic 16 and B decision.Yet, unlikely be subjected to the influence of described dip plane away from the liquid crystal molecule of element characteristic 16, thus be positioned at along the liquid crystal molecule 17c (being called " central element " afterwards) of thickness of liquid crystal layer direction mid-plane almost the normal direction with respect to substrate 15 do not tilt.

Then, in the height H of the face A that changes each element characteristic 16 and the area ratio between the face B and each element characteristic 16, similarly simulate; The result has been shown among Fig. 5.Ratio A/P of the width of the transverse axis presentation surface A of Fig. 5 chart and the repetition period P of element characteristic 16, and the major axis and the angle between the substrate surface (inclination angle) of Z-axis central element when representing not apply voltage.From the result shown in Fig. 5 as can be seen, although changed the face A of each element characteristic 16 and area ratio and the height H between the face B, occurred and the similar trend of the analog result shown in Fig. 4.Central element tilts with respect to the substrate normal direction hardly.

Analog result shown in the Figure 4 and 5 demonstrates element characteristic 16 can not give sufficient pre-dumping (for example about 87 ° or about 93 ° inclination angle to being positioned at along the liquid crystal molecule of thickness of liquid crystal layer direction mid-plane; In other words, about 3 ° angle between liquid crystal molecule and the substrate normal).Possible reason is as follows.

When orientation control will realize by friction treatment, the thickness direction that the liquid crystal aligning that is determined at the interface between liquid crystal layer and the substrate (alignment films) will stride across liquid crystal layer kept.On the other hand, when orientation control will be when being formed on the lip-deep concavo-convex realization that contact with liquid crystal layer (as shown in Figure 4), liquid crystal molecule will be according to described concavo-convex orientation, needs only describedly concavo-convexly to be become by small (for example 10 μ m or littler) pattern groups.Yet around under the influence of environment, liquid crystal molecule will reorientation, so that make minimise stress according to distribution of orientations.Thereby, anyly can be balanced (averaged out) gradually along the thickness direction of liquid crystal layer by concavo-convex localized variation (vergence direction and angle of inclination) of giving liquid crystal molecule 17.

Therefore, the size of only dwindling element characteristic 16 can not be applied to liquid crystal display device based on (undulation-based) orientation control that rises and falls.In order to be applied to liquid crystal display device, P average period of element characteristic must keep being not less than 10 μ m, and the shape and size of element characteristic 16 also need optimization, so that can stride across the thickness direction control liquid crystal aligning of liquid crystal layer.

The present inventor has done careful discovering, for the thickness direction that can stride across liquid crystal layer obtains liquid crystal aligning, having a mind to introduce a kind of disclination (just being orientated defective) at the near surface of the vertical alignment layer that is used for liquid crystal layer is effectively, and this specifically describes with reference to Fig. 7 A and 7B.Fig. 7 A and 7B have illustrated the example that carries out aligned liquid crystal layer control by the substrate 30 that uses its surface to be provided with element characteristic 31, and each element characteristic 31 all has the xsect of parallelogram form.

Fig. 7 A is the liquid crystal aligning that shows in the situation that does not have disclination.As can be seen from Figure 7, at the near surface of element characteristic 31, the orientation of liquid crystal molecule 32c and 32d is respectively by the face C of component units feature 31 and face D restriction.As a result, the liquid crystal molecule 32c that is positioned on the face C tilts to different direction respectively with liquid crystal molecule 32d on being positioned at face D.Yet along with get over away from element characteristic 31 position of liquid crystal molecule, these vergence directions become and are balanced more, consequently are positioned at along the liquid crystal molecule 33 of thickness of liquid crystal layer direction mid-plane to be approximately perpendicular to substrate 30 orientations.

On the other hand, as shown in Fig. 7 B, can be by the shape and/or the arrangement optimization of element characteristic 31 be had a mind to produce disclination.In Fig. 7 B, can not on the thickness direction of liquid crystal layer, keep continuity by the orientation of the liquid crystal molecule of the inclined side (face C) of element characteristic 31 restriction with by the orientation of the liquid crystal molecule of substrate surface (bottom surface) restriction, therefore in the region generating disclination that is clipped between face C and the substrate surface.Because because the continuity of orientation has been broken in this disclination, so can not be sent to any liquid crystal molecule away from face C from the dipole-dipole force of face C.As a result, reduced face C and be applied to the influence on the liquid crystal molecular orientation in the whole liquid crystal layer, and the dipole-dipole force of face D becomes and dominates.In this state, the liquid crystal molecular orientation that is limited by side (face C) can be described as " being limited in the space ".

According to the present invention, utilize the disclination shown in Fig. 7 B to come roughly to control equably the orientation that is positioned at along the liquid crystal molecule 33 of thickness of liquid crystal layer direction mid-plane.

Can on any surface that contacts with liquid crystal layer (for example the TFT substrate of liquid crystal display device or color filter substrate), aforesaid concavo-convex (orientation control structure) be set.In this manual, its surface be provided with the orientation control structure any substrate (comprising TFT substrate, color filter substrate, glass substrate etc.) be called " orientation control element " jointly.

Afterwards, the exemplary configurations that the present invention is orientated control element is described with reference to the accompanying drawings.

Fig. 8 A is the skeleton view that comprises the orientation control element 20 of element characteristic 31, and each element characteristic 31 all has quadrangular cross section.Fig. 8 B is the E-E ' cross-sectional view of orientation control element 20.

On the surface of orientation control element 20, element characteristic 31 is arranged in two-dimensional array.Each element characteristic 31 all has the asymmetric xsect along directions X.Orientation control element 20 has a plurality of grooves 35 that are formed on wherein.Each groove 35 all extends being not orthogonal on the direction of directions X, and can for example extend along directions X.

Utilize the orientation control element 20 can be, promptly produce disclination in each zone 21 that surrounds by the sidewall and the substrate surface of adjacent cells feature in the shadow region shown in Fig. 8 B.For liquid crystal aligning being limited in the zone 21, must for example pass through, the adjustment form surface construction is come in the gap that fully reduces between the adjacent cells feature.The concrete size and the spacing of element characteristic will be discussed afterwards.Element characteristic can have any asymmetric shape of cross section, for example triangle.

In order to stop liquid crystal molecule when applying high voltage, on azimuth direction, to rotate, the groove 35 in the orientation control element 20 is set, it is described below.

As above described with reference to Fig. 2 A and 2B, in the VAN pattern, liquid crystal molecule vertical orientated when not applying voltage (Fig. 2 A).When striding across liquid crystal layer and apply voltage, liquid crystal molecule becomes and is parallel to substrate orientation (Fig. 2 B).If in orientation control element 20, do not form groove 35, when taking when applying voltage near the liquid crystal molecule on orientation control element 20 surfaces when being parallel to the attitude of substrate, according to Fig. 6 A and 6B in the similar principle of description done about liquid crystal molecule 17, liquid crystal molecule will manage to be orientated on the gap direction between the element characteristic.Extend on the direction of liquid crystal molecular orientation direction when not applying voltage in gap between the element characteristic.Thereby when voltage raises, the motion of liquid crystal molecule will become the motion on the azimuth direction from the motion of polar angle direction.This just makes boosted voltage become difficult in the white show state to be used in, thereby has hindered satisfied demonstration.

On the other hand, if in orientation control element 20 groove 35 is set, as shown in Fig. 8 A, liquid crystal molecule will be managed along groove 35 orientations when applying voltage, thereby stop the rotation on azimuth direction.

Each element characteristic 31 all is asymmetric with respect to the plane perpendicular to directions X and substrate surface.Therefore, the surface of orientation control element 20 is asymmetric with respect to azimuth direction.In other words, the height on orientation control element 20 surfaces makes different with the height change cycle along the Y direction along the height change cycle of directions X along all being periodically variable on directions X and the Y direction perpendicular to directions X.Therefore, by being set, orientation control element 20 make its surface contact with liquid crystal layer, not only can be when not applying voltage based on the shape of cross section (it is asymmetric along directions X) of each element characteristic 31 and give the liquid crystal layer pre-dumping, and can when applying high voltage, limit liquid crystal molecular orientation based on variation (is example with periodicity groove 35) along Y direction upper level.

Therefore, orientation control element 20 concavo-convex not only aspect shape of cross section, and be optimized at the vpg connection along depth direction.Therefore, in black display state and white show state, can control liquid crystal aligning.The result can obtain high-quality demonstration.

Use the exemplary orientation control element 20 that illustrates among Fig. 8 A and the 8B, by breaking continuity on the thickness of liquid crystal layer direction, being used to from the dipole-dipole force of the dip plane of element characteristic 31 C and the dipole-dipole force of substrate surface, produced disclination, this is described with reference to Fig. 7 A and 7B.Perhaps, can produce disclination by the orientation continuity of breaking in the liquid crystal layer plane.

To describe afterwards as reference Fig. 9 A and 9B, orientation control element 40 shown in Fig. 8 C and the 8D works, make by roughly with respect to can not keeping continuity in the orientation of the liquid crystal molecule 17w of the side restriction of the vertically extending element characteristic 41 of substrate surface and the plane that is oriented in liquid crystal layer, thereby produce disclination along the side of each element characteristic 41 by the liquid crystal molecule 17g of substrate surface (bottom surface) restriction.Because this disclination, by be oriented to " being limited in the plane domain " of the liquid crystal molecule of the side restriction of element characteristic 41, this plane domain is determined by bottom surface 42, and is roughly surrounded by the side of each element characteristic 41.

Will be described below the exemplary orientation control element structure that in plane domain, produces disclination.

Fig. 8 C shows that the present invention is orientated the skeleton view of another exemplary configurations of control element.Orientation control element 40 shown in Fig. 8 C comprises a plurality of triangular prism shape element characteristics 41.The upper surface of each element characteristic 41 for example is an isosceles triangle.Fig. 8 D is the planimetric map of orientation control element 40.From these figure as can be seen, each gap (depression) of 41 of adjacent cells features all has the bottom surface 42 that is shaped as isosceles triangle.

When with orientation control element 40 aligned liquid-crystals, liquid crystal aligning can be limited in the plane domain of determining by bottom surface 42.To with reference to Fig. 9 A and 9B this principle be described below.

Fig. 9 A and 9B are planimetric map and the Z-Z ' cross-sectional views that is presented between orientation control element 40 and the liquid crystal layer interface liquid crystal molecular orientation at the interface respectively.As shown in the figure, be orientated to upper surface near the liquid crystal molecule 17p of each element characteristic 41 upper surface perpendicular to element characteristic 41.42 places, bottom surface in each gap (depression) between element characteristic 41, liquid crystal molecule 17b are forced to being parallel to bottom surface 42 and being approximately perpendicular on the direction on base of the isosceles triangle that limits bottom surface 42 and are orientated.Because the influence of the liquid crystal molecule 17b at 42 places in the bottom surface, the orientation of other liquid crystal molecule 17g in the gap of each element characteristic 41 roughly is similar to liquid crystal molecule 17b, just is positioned near the orientation of the liquid crystal molecule 17w of each side-walls of each element characteristic 41 sidewall perpendicular to each element characteristic 41.

Therefore, at liquid crystal layer and 40 of control elements of orientation at the interface, mainly contain two kinds of orientations in the highest flight: the orientation of the orientation of the bottom surface 42 liquid crystal molecule 17b of place and the element characteristic 41 liquid crystal molecule 17p of upper surface place.Liquid crystal molecule in the whole liquid crystal layer is being orientated on the direction in conjunction with these two kinds of orientations fifty-fifty, thereby causes in certain party acclivitous vertical orientated.In other words, the control of orientation in this liquid crystal layer can realize by two kinds of orientations of giving the interface liquid crystal molecule above controlling, and ignores any other orientation (for example, near the liquid crystal molecule 17w of element characteristic 41 sidewalls orientation).

The shape of the shape of the upper surface of each element characteristic 41 and bottom surface 42 is not limited to the shape shown in Fig. 8 C and the 8D.Yet, have to be noted that if bottom surface 42 has the shape (for example, equilateral triangle, square, rectangle) that has rotation axes of symmetry on the substrate normal direction, the interface liquid crystal molecule near the bottom surface is orientated on specific direction.Therefore, bottom surface 42 must not have symmetrical turning axle on the substrate normal direction.

The structure (for example orientation control element 40 shown in Fig. 8 C and the 8D) that produces disclination in plane domain is than the easier manufacturing of structure (for example orientation control element 20 shown in Fig. 8 A and the 8B) that produces the space disclination.In the situation of the structure that produces the space disclination, the surface of orientation control element need have concavo-convex (as illustrational by the element characteristic 31 of orientation control element 20) that changes along the thickness of liquid crystal layer direction.Yet, with conventional exposure device be difficult to make along thickness direction change concavo-convex.On the other hand, produce in the situation of structure of disclination at plane domain being used for, can so form concavo-convex, promptly always with respect to substrate vertical (is example with triangular prism shape element characteristic 41), therefore can be with through being usually used in the exposure device that display device is made, for example substep projection mask aligner (stepper) makes.

By using aforesaid orientation control element 20 or 40, the liquid crystal display device that for example can obtain to have the structure shown in Figure 10 A or the 10B.

In the display device shown in Figure 10 A 700, orientation control element 483 is relative with substrate 480, wherein be orientated control element 483 and have and be formed on its lip-deep conducting film 485 and vertical alignment layer 487 successively, substrate 480 has and is formed on its lip-deep vertical alignment layer 488 and electrode 481.Liquid crystal layer 490 is clipped between orientation control element 483 and the substrate 480.Vertical alignment layer 487 contacts formation with liquid crystal layer 490.Liquid crystal layer 490 is vertical alignment-type liquid crystal layers.Orientation control element 483 has the contoured surface of describing to 8D with reference to Fig. 8 A, the concavo-convex liquid crystal molecular orientation that is used for causing liquid crystal layer 490.

Do not striding across under the state that liquid crystal layer 490 applies voltage (OFF attitude), the liquid crystal molecule (central element) that is included in the liquid crystal layer 490 is orientated the surperficial structure influence of control element 483, thereby tilts from the normal direction of substrate.When striding across liquid crystal layer 490 by conducting film 485 and electrode 481 and apply voltage, liquid crystal molecule further tilts in their directions in the medium dip of OFF attitude.

Replace substrate 480, can use another orientation control element relative, so that liquid crystal layer 490 is clipped between two orientation control elements with orientation control element 483.

Display device 701 shown in Figure 10 B has the structure similar to the display device 700 shown in Figure 10 A.Yet, in display device 701, between substrate and orientation control element 484, form conducting film 482.

Do not consider their shapes, the element characteristic of orientation control element 483 can be formed by the organic substance of for example acryl resin or rubber (for example photoresist, UV cured resin, thermosetting resin or epoxy resin), or (for example by metal for example, Al, Ta, or Cu), semiconductor (for example Si or ITO) or insulating material (SiO for example ₂Or SiN) dead matter form.The preferred cell feature forms by having the material (for example fluoroplastic) that makes liquid crystal produce vertical orientated characteristic, because so no longer must apply vertical alignment layer 488 on the surface of orientation control element 483, can simplify manufacturing process thus.

Use display device 700 and 701,, therefore can roughly control the orientation of central element in the liquid crystal layer 490 equably, so can obtain the demonstration of high-contrast because it is lip-deep concavo-convex to be arranged on orientation control element 483.Shape and/or arrangement by element characteristic in the control orientation control element 483 or 484 can be provided with any liquid crystal aligning arbitrarily (being vergence direction and the angle of inclination of liquid crystal molecule from the substrate normal).In addition, compare delay that can be improved and aperture opening ratio with the display device that is equipped with conventional orientation control assembly (for example rib or otch).

Preferably, display device 700 and 701 is MVA mode liquid crystal display devices.In the situation that applies the present invention to the MVA mode liquid crystal display device, can come freedom to cut apart by the concavo-convex relative ad-hoc location (coordinate) that forms thereon on the irregular substrate of controlling orientation control element 483 with easily realizing being orientated.In other words, the concavo-convex farmland that becomes definition MVA mode liquid crystal display device.Because needn't form orientation control device (for example rib or otch), so can simplify manufacturing process as the complexity in the conventional situation.

In addition, display device 700 with 701 be also advantageous in that with the display device that utilizes rib or otch mutually specific energy realize the better response characteristic.Below this advantage will be described.

For each pixel, be used in the conventional MVA mode liquid crystal display device orientation control assembly (as rib or otch) only partly (one-tenth one-dimensional array) be configured in the liquid crystal layer.Therefore, in actual each pixel with two-dimensional development, can quickly respond to relatively near the liquid crystal molecule of orientation control element, and slack-off in any liquid crystal molecule response of the position that unlikely receives the influence of orientation control assembly.This response characteristic distributes and causes relatively poor display characteristic.

In the situation of rib technology, because the influence of rib shape, so near the liquid crystal molecule that is present in the rib has predetermined pre-dumping (pre-dumping direction and tilt angle).On the other hand, be positioned at the influence that the middle any liquid crystal molecule of adjacent rib unlikely is subjected to the rib shape, so the tilt angle of this liquid crystal molecule is littler than near the tilt angle of the liquid crystal molecule the rib.When striding across such liquid crystal layer and apply voltage, liquid crystal molecule will only tilt on the pre-dumping direction in succession, at first be those liquid crystal molecules that have than big tilt angle, thereby reduce the response speed of liquid crystal layer.

Similarly, in the fringing field technology, being present near the liquid crystal molecule of otch will be than being present in the influence that the middle liquid crystal molecule of otch is subjected to bigger fringing field.As a result, when applying voltage, liquid crystal molecule will be only response one by one, at first be more near those liquid crystal molecules of otch, thereby cause the liquid crystal layer response time to prolong.

On the other hand, according to above-mentioned display device 700 and 701, can on whole pixel region roughly, be formed uniformly (two dimension) orientation control device on the plane of liquid crystal layer 490, make liquid crystal molecule to respond fast, and no matter the particular location in liquid crystal layer 490.As a result, the response speed of liquid crystal layer 490 can improve greatly from the level of routine.

Should be noted that the liquid crystal aligning control of carrying out among the ZBD (top bistable device (Zenithal Bistable Device)) that also can in the bi-stable liquid crystals pattern, work based on rising and falling.Orientation control among the ZBD has for example been described in open No.2002-500383 of Japanese national phase and 2003-515788.In ZBD, existence will by the alignment films that rises and falls determine more than two liquid crystal aligning state (pre-dumping), these state of orientation change mutually by the voltage that applies opposed polarity.Each state of orientation remains intact when not applying voltage.On the other hand, according to the present invention, can not respond applying of opposed polarity voltage (for example in scope) and change from-5V to+5V by concavo-convex definite state of orientation (tilt angle, pre-dumping direction) of orientation control element; In other words, can not demonstrate bistable state.The influence that the transmission of noticing the bistable liquid crystal mode liquid crystal display device applied by response voltage and producing lags behind, and liquid crystal display device of the present invention does not have this transmission to lag behind, so can realize outstanding gray level display.

(embodiment 1)

Afterwards, structure according to the liquid crystal display device of embodiment of the present invention 1 is described with reference to the accompanying drawings.

Figure 11 A and 11B are the schematic cross section of explanation liquid crystal display device exemplary configurations of the present invention.Liquid crystal display device shown in Figure 11 A comprises: by spacer 65 (thickness: a pair of orientation control element 50 that links together 5 μ m), and be clipped in liquid crystal layer therebetween 66.Orientation control element 50 comprises glass substrate 61 and the electrode 62 that is formed on the glass substrate 61, forms the orientation control structure on electrode 62.The orientation control structure comprises the arrangement of a plurality of element characteristics 51.Element characteristic 51 is for example formed by resin material.Each element characteristic 51 all has asymmetric quadrangular cross section.In this orientation control structure, on direction, be formed with the groove (not shown) perpendicular to element characteristic 51 orientations.On the surface of element characteristic 51, be formed with vertical alignment layer 64.Vertical alignment layer 64 contacts with liquid crystal layer 66.

Liquid crystal display device shown in Figure 11 B comprises orientation control element 50, sets off by contrast at the end (counter substrate) 61 ' and is clipped in liquid crystal layer therebetween 66.Orientation control element 50 has the structure similar to the orientation control element 50 of the sample device shown in Figure 11 A.Setting off by contrast the end 61 ' comprises electrode 62 and is formed on electrode 62 lip-deep vertical alignment layers 64.The surface that is arranged on the vertical alignment layer 64 that sets off by contrast is smooth at the end 61 '.

In having these two kinds of structures, in any liquid crystal display device, can give liquid crystal molecule pre-dumping in the liquid crystal layer 66 by the shape and/or the arrangement of control module feature 51.Yet, the tilt angle of noticing the central element (promptly being arranged in) in the liquid crystal display device shown in Figure 11 B along the liquid crystal molecule of liquid crystal layer 66 thickness direction mid-planes be the liquid crystal display device shown in Figure 11 A central element tilt angle about 1/2.

Although the orientation control element 50 that is used in the present embodiment liquid crystal display device comprises the element characteristic 51 with quadrangular cross section, the shape of cross section of element characteristic 51 can be triangle or any other shape, as long as it is asymmetric.

Figure 12 A is the skeleton view of another exemplary configurations of explanation the present embodiment orientation control element.Orientation control element 70 shown in Figure 12 A comprises multirow 71c element characteristic.Every capable 71c element characteristic all comprises a plurality of element characteristics 71 with spacing P of arranging along directions X.Each element characteristic 71 all has the xsect of general triangular.The capable 71c of element characteristic arranges with predetermined space (groove 72) along the Y direction, and spacing is PG.Groove 72 extends along directions X.Here, each groove 72 is defined as width G along the length of Y direction.

When using orientation control element 70 structure liquid crystal display devices, this described with reference to Fig. 8 A, and liquid crystal molecule will manage to have stoped liquid crystal molecule to rotate on azimuth direction thus along groove 72 orientations when applying high voltage.Preferably, groove 72 has the shape of cross section (for example rectangle) along Y direction symmetry.Therefore, can stop the rotation of liquid crystal molecule when applying high voltage under the situation that does not influence pre-dumping, described pre-dumping is determined by the shape of cross section along asymmetric each element characteristic 71 of directions X.

The orientation control element 70 of the present embodiment is not limited to the structure shown in Figure 12 A, but can adopt any structure, as long as not only can control the shape of cross section of each element characteristic, and can control along the shape of each element characteristic of depth direction, on azimuth direction, rotate just when applying high voltage to stop liquid crystal molecule.For example, can adopt the structure shown in Figure 12 B, wherein the capable 73c ' of the capable 73c of element characteristic and element characteristic along the Y direction alternately, wherein the every capable 73c ' of element characteristic is the same with the every capable 73c of element characteristic along directions X, the every capable 73c of element characteristic along the directions X translation 1/2 spacing P.

In the structure shown in Figure 12 A or the 12B, the surface elevation of orientation control element 70 changes with spacing P along directions X, changes with spacing PG along the Y direction.Along the height change of directions X with different along the height change of Y direction.Can distinguish and select arbitrarily, and spacing P and PG can equate or unequal along the spacing P of directions X with along the spacing PG of Y direction.Even, also can obtain the aforementioned effect that stops liquid crystal molecule when applying high voltage, to rotate along little unlike along the spacing P of directions X of the spacing PG of Y direction.For example,, and be used for giving orientation, when striding across liquid crystal layer and apply high voltage, just can not observe the problematic variation on the azimuth direction to liquid crystal layer if under P=1 μ m, PG=5 μ m and G=1 μ m condition, make orientation control element 70.Note,, then can suppress the variation on the azimuth direction most effectively if for example the width G of groove 72 is not less than 0.5 μ m and is not more than 10 μ m.

Give to the pre-dumping direction of liquid crystal layer and tilt angle mainly according to determining along each element characteristic 71 of directions X or 73 shape of cross section.Therefore, even only change along the shape on element characteristic 71 or 73 depth directions, keep their shape of cross section simultaneously, then remarkable change can not take place in pre-tilt yet.At exercise question be＜be orientated the discussion of each parameter of control structure〉below discuss in the part, studied each parameter that limits the element characteristic shape of cross section.Notice that the result of research will be the influence that is not subjected to shape or spacing, the existence of groove 72 or does not have groove 72 basically.Yet, having in the situation of orientation control element of the structure shown in Figure 11 B in use, the actual tilt angle of giving to liquid crystal layer trends towards littler than the tilt angle of being determined by the shape of cross section of element characteristic 71 or 72.Therefore in this case, must adjustment unit feature 71 or 73 shape of cross section, to obtain the tilt angle of expectation.

Can make any orientation control element of the present embodiment by using beamwriter lithography device for example.Afterwards, as an example method of making orientation control element 70 will be described.

At first, form photoresist layer (thickness: for example 1 μ m) by being spin-coated on the substrate surface.Here, have the glass substrate that is formed on its lip-deep conducting film and be used as substrate, THMR-IP3300 is as photoresist.

Next, the photoresist layer is processed into fine pattern.Here, will form the element characteristic of arranging shown in Figure 12 A 71.More particularly, by using the beamwriter lithography device, the photoresist layer is exposed develop then.By when exposing, changing the beam intensity of exposure device, can form the dip plane (sidewall) of element characteristic 71.

Behind graphical photoresist layer, vertical alignment layer is coated on the exposed surface of substrate.Thereby, obtained orientation control element 70.

The method of making the orientation control element of the present embodiment is not limited to top described.For example, can use holographic technique or two-beam interference exposure technique.In the situation of use interfering exposure, form after the concavo-convex striped by interfering exposure, can on perpendicular to the direction of striped, form groove 72 with spacing PG.Can form groove 72 by etching or laser ablation.

Can use the orientation control element of for example making 70 to make the liquid crystal display device of the present embodiment by said method.Specifically, have in the situation of the liquid crystal display device of structure shown in Figure 11 A, form two orientation control elements 70, and link together by spacer with 5 μ m thickness in manufacturing.Afterwards, the liquid crystal material that will have a negative Δ ε is injected between the orientation control element 70.As liquid crystal material, use MLC6609 (MERCK﹠amp; CO., Inc.).Have in the situation of the liquid crystal display device of structure shown in Figure 11 B in manufacturing, can use similar methods, different being to use is formed with in the end 61 ' the orientation control element 50 one of setting off by contrast of electrode 62 and vertical alignment layer 64 on it.

In the present embodiment, by the orientation control of the lip-deep concavo-convex realization liquid crystal layer of orientation control element.At this moment, in order roughly to control the orientation of the central element in the liquid crystal layer equably, must in zone (space), produce disclination, as shown in Fig. 7 B near orientation control element near surface.

The inventor has done special research to the possible surface structure (orientation control structure) of the orientation control element that is used to produce disclination.The result is discussed below.

The discussion of each parameter of＜orientation control structure 〉

At first, will each parameter of definition orientation control structure be described.

Figure 13 A and 13B are respectively the skeleton view and the cross-sectional views of orientation control element 50.On orientation control element 50 surfaces, arrange a plurality of element characteristics 51.The shape of cross section of each element characteristic 51 is roughly trapezoidal.In the cross-sectional view of Figure 13 B, the spacing of element characteristic 51 is represented with " P "; The height of each element characteristic 51 is represented with " H "; The upper surface width of each element characteristic 51 is represented with " W "; Angle (base angle) between each sidewall of substrate surface and each element characteristic 51 is represented with " A " and " B "; Gap width between the adjacent cells feature 51 is represented with " F ".The spacing P of element characteristic 51 is not less than 1 μ m as previously described, and is not more than 10 μ m.Should suitably select these parameters P, H, W, A, B and F according to the concrete pre-dumping that will give liquid crystal layer.

Angle A between one of sidewall of the shape of cross section of each element characteristic and the substrate surface can be 90 ° or bigger; In this case, above-mentioned parameter in Figure 13 C definition.The shape of cross section of each element characteristic can be chosen as triangle; In this case, the width W of upper surface is zero.

In this manual, " pre-dumping direction " is defined as the vergence direction (liquid crystal director) on the plane that liquid crystal molecule when not applying voltage to liquid crystal layer projects to substrate surface.As shown in Figure 14 A and 14B, the vergence direction of liquid crystal molecule and the viewpoint definition between the substrate surface are " inclination angle [theta] ".In addition, as shown in Figure 14 A, in the situation of horizontal alignment type liquid crystal layer, the vergence direction and the viewpoint definition between the substrate surface of liquid crystal molecule is " tilt angle Ph ".On the other hand, as shown in Figure 14 B, in the situation of vertical alignment-type liquid crystal layer, the viewpoint definition between the vergence direction of long axis of liquid crystal molecule and the substrate normal is " tilt angle Pv ".Therefore, tilt angle Ph equals inclination angle [theta] (Ph=θ), and tilt angle Pv equals (90-θ) °.

For the above-mentioned parameter of research orientation control structure, the inventor has made the sample device with structure shown in Figure 11 A.Below manufacture method will be described.

At first, manufacturing will be used for the orientation control element 50 of sample device.

On the surface of transparent substrates, for example form photoresist layer (thickness: 1 μ m) by spin coating.In the present embodiment, THMR-IP3300 is as photoresist.In the present embodiment, the glass substrate 61 that is formed with conductive layer (ITO) 62 on its surface is as transparent substrates.

Next, by using two-beam interference exposure figure photoresist layer.Specifically, as shown in Figure 15 A, in interfering exposure device, substrate 61 is placed on prism, and (prism angle: φ) above 69, this prism is arranged on above the Al catoptron 68.Substrate 61 is exposed to Kr laser 67 with 407nm wavelength.As shown in Figure 15 B, the light that incides on the substrate with incident angle i is conducted through substrate, in prism, reflect, then from the Al mirror reflects, and afterwards with emergence angle γ once more from the substrate surface outgoing.As a result, the photoresist layer can experience the desired intensity distribution.After the exposure, develop, on the surface of substrate 61, formed thus and have 1 μ m or littler height and element characteristic 51 with asymmetric quadrangular cross section.This patterning process is favourable, because can the spacing of element characteristic 51 dip plane and angle etc. freely be set according to incident angle i, prism angle φ, prismatic refraction rate etc.

Afterwards, vertical alignment layer 64 is coated on the surface of the substrate 61 that is formed with element characteristic 51 on it.Thereby obtained orientation control element 50.

Be orientated control elements 50 by using said method to form two, and final orientation control element 50 linked together by spacer 65.Then, liquid crystal material is injected between the orientation control element 50.As liquid crystal material, use liquid crystal MLC6609 (MERCK﹠amp with negative Δ ε; CO., Inc.).Therefore, made sample device with structure shown in Figure 11 A.

(A) discussion of the spacing P of element characteristic

At first, with the spacing P of discussion unit feature and the relation between the liquid crystal aligning.Here, the height H of supposing each element characteristic 51 is 0.5 μ m; Angle B between one of sidewall and the substrate surface is 75 °; The width W of upper surface is 0; The gap width that the adjacent cells feature is 51 is 0.Use six sample devices (No.1 to 6) of the spacing P variation as shown in table 1 of its element characteristic 51.Angle A between another sidewall and the substrate surface changes according to spacing P.

Measured the inclination angle in the original alignment (orientation when promptly not applying voltage) of sample device No.1 to 6, the result is presented in the table 1.

Table 1

Sample device No.	??1	??2	??3	??4	??5	??6
							Spacing P (μ m)	??20	??10	??5	??1	??0.8	??0.5
Inclination angle [theta] (°)	??90	??89.7	??89	??88	??85	??80
							Tilt angle Pv (°)	??0	??0.3	??1	??2	??5	??10

Can understand from table 1, when the spacing P of element characteristic 51 is approximately 10 μ m or more hour can gives to the liquid crystal layer pre-dumping.Yet,, must reduce spacing P (for example 1 μ m or littler) in order to obtain sufficient pre-dumping.Possible reason is as follows.

If the spacing P of element characteristic 51 is big, show as analog result by Fig. 7 A, the liquid crystal aligning that comes from orientation control element 50 surfaces will be balanced in the mid-plane along the thickness of liquid crystal layer direction, so that these liquid crystal molecules tilt from the substrate normal direction hardly.On the other hand, if reduce spacing P,, between adjacent cells feature 51, produce the part (disclination) of restriction liquid crystal aligning, thereby suppress the balance of liquid crystal aligning as what show by the analog result of Fig. 7 B.As a result, even in the mid-plane along the thickness of liquid crystal layer direction, liquid crystal molecule still can be orientated to from the substrate normal slope.

(B) discussion of the height H of each element characteristic

Next, with the height H of discussion unit feature and the relation between the liquid crystal aligning.Here, the spacing P that supposes each element characteristic 51 is 1 μ m; Angle B between one of sidewall of element characteristic 51 and the substrate surface is 75 °; The width W of upper surface is 0; The gap width F that the adjacent cells feature is 51 is 0.Use six sample devices (No.7 to 12) of the height H variation as shown in table 2 of its element characteristic 51.Another sidewall of each element characteristic 51 and the angle A between the substrate surface change according to height H.Because W=0, so each element characteristic 51 all has leg-of-mutton shape of cross section.

When applying low-voltage (2 to 3V), passes through the liquid crystal layer of giving sample device No.7 to 12 the orientation homogeneity of visual observation evaluating liquid crystal layer.The result has been shown in the table 2.In table 2, the orientation homogeneity is expressed as " good " (zero), " a little at random " (△) or " at random " (*).

Table 2

Sample device No.	??7	??8	??9	??10	??11	??12
							Height H (μ m)	??0.1	??0.2	??0.5	??0.8	??1	??1.5
The orientation homogeneity	??×	??△	??△	??○	??○	??○

As can be seen from Table 2, if element characteristic has enough big height H, then in each zone that liquid crystal aligning can be limited in being surrounded by the fluctuating feature, so give roughly pre-dumping uniformly can for the central element in the whole liquid crystal layer.Therefore, when applying voltage, central element can tilt in the direction of expectation.

Orientation when applying voltage by checking when spacing P that changes element characteristic 51 and the height H, can determine when H/P is equal to or greater than 0.1, can obtain good substantially orientation, and when H/P is equal to or greater than 0.5 even can obtain more orientation control uniformly.

(C) discussion of the upper surface width W of each element characteristic

With the relation of discussing between each element characteristic upper surface width W and the liquid crystal aligning.Here, the spacing P that supposes element characteristic 51 is 1 μ m; The height H of each element characteristic 51 is 0.5 μ m; Angle B between one of sidewall and the substrate surface is 75 °; The gap width F that the adjacent cells feature is 51 is 0.As shown in table 3 and four the sample devices (No.13 to 16) that change of upper surface (top portion) width W of using its element characteristic 51.Angle A between another sidewall and the substrate surface changes according to width W.

Note, by control will be by interfering exposure figureization the thickness of photoresist layer and time shutter and the development time width W that changes upper surface.

Measured the inclination angle [theta] of sample device No.13 to 16 in original alignment.The result has been shown in the table 3.

Table 3

Sample device No.	??13	??14	??15	??16
					Upper surface width W (μ m)	??0.8	??0.5	??0.2	??0
The inclination angle (°)	??90	??89	??88.5	??88
					Tilt angle Pv (°)	??0	??1	??1.5	??2

As can be seen from Table 3, along with the increase of each element characteristic 51 upper surface width W, the inclination angle becomes near 90 °; In other words, tilt angle Pv becomes near zero.

(D) discussion of the gap width F between the adjacent cells feature

With gap width F between discussion adjacent cells feature and the relation between the liquid crystal aligning.Here, the height H of supposing each element characteristic 51 is 0.5 μ m; Angle B between one of sidewall and the substrate surface is 75 °; And the width W of upper surface is 0.Use four sample devices (No.17 to 20) of the gap width F variation as shown in table 4 of 51 of adjacent cells features wherein.Angle A between another sidewall and the substrate surface changes according to gap width F.

Measured the inclination angle [theta] of sample device No.17 to 20 in original alignment.The result has been shown in the table 4.

Table 4

Sample device No.	??17	??18	??19	??20
					Element characteristic gap width F (μ m)	??2	??1	??0.5	??0
The inclination angle (°)	??90	??70	??80	??88
					Tilt angle Pv (°)	??0	??20	??10	??2

As can be seen from Table 4, the increase along with the gap width F of 51 of adjacent cells features more disclination may take place, and tilt angle Pv will increase.Yet if gap width F too big (for example 2 μ m or bigger), tilt angle Pv can be reduced to 0 °.This may be because the spacing P of element characteristic 51 increases along with undue the increasing of gap width F, thereby causes liquid crystal aligning to be balanced.In other words, when gap width F increases, generally can obtain the pre-dumping that shows as analog result by Fig. 7 B; Yet in case gap width F equals 2 μ m or bigger, liquid crystal aligning will become along the thickness direction of liquid crystal layer and be balanced, as by shown in the analog result of Fig. 7 A, so no longer can obtain pre-dumping in liquid crystal layer.

(E) discussion of the Sidewall angles A of each element characteristic

To the Sidewall angles A of each element characteristic and the relation between the liquid crystal aligning be discussed.Here, the height H of supposing each element characteristic 71 is 0.5 μ m; Angle B between sidewall and the substrate surface is 60 °; The width W of upper surface is 0; The gap width F that the adjacent cells feature is 71 is 0.Use wherein another sidewall of each element characteristic 71 and five sample devices (No.21 to 25) of the angle A variation as shown in table 5 between the substrate surface.The spacing P of element characteristic 71 changes according to angle A.Because W=0, so each element characteristic 71 all has leg-of-mutton shape of cross section.

Notice, the sample device No.1 to 20 that (A) uses in the discussion of (D) above being unlike in, the orientation control structure of sample device No.21 to 25 forms by use beamwriter lithography device.

When the liquid crystal layer of giving sample device No.21 to 25 applies low-voltage (2 to 3V), the orientation homogeneity of coming the evaluating liquid crystal layer by visual observation.The result has been shown in the table 5.In table 5, similar with table 2, the orientation homogeneity is expressed as " good " (zero), " a little at random " (△) or " at random " (*).

Table 5

Sample device No.	??21	??22	??23	??24	??25
						Sidewall angles A (°)	??5	??15	??30	??45	??90
Spacing P (μ m)	??6.0	??2.2	??1.2	??0.7 ??9	??0.2 ??9
						The orientation homogeneity	??×	??×	??×	??△	??○

From the result of table 5 as can be seen, when the angle B of a sidewall is fixed on 60 °, along with the increase of another sidewall angle A can obtain better orientation.Optimized angle A is equal to or greater than 45 °.

As mentioned above, shape and/or arrangement optimization by with element characteristic 51 can obtain the pre-dumping of expectation in liquid crystal layer.Shape (angle of dip plane, area etc.) by change unit feature 51, size, spacing etc. can stably obtain pre-dumping arbitrarily (tilt angle, pre-dumping direction).Because the definite pre-dumping directions such as inclination angle by the sidewall of each element characteristic 51 it should be understood that, can be easy to realize that orientation cuts apart by the shape that changes element characteristic 51 according to the ad-hoc location on the substrate surface, for example the MVA pattern.

(embodiment 2)

Afterwards, liquid crystal display device according to embodiment of the present invention 2 is described with reference to the accompanying drawings.The liquid crystal display device of the present embodiment has and the embodiment 1 similar structure of describing with reference to Figure 11 A and 11B, except following difference.

The orientation control element that uses in the embodiment 1 comprises a plurality of element characteristics, and each element characteristic all has asymmetric shape of cross section.Therefore, in embodiment 1, produce disclination by utilizing by form concavo-convex of element characteristic liquid crystal aligning is limited in specific region or the space.On the other hand, the orientation control element of the present embodiment comprises a plurality of pillar cell features, and each all has the sidewall perpendicular to substrate surface.By using this orientation control element (being described) in the above, can produce disclination in the plane domain by the definition of the bottom surface in each gap (depression) between element characteristic by liquid crystal aligning is limited in reference to Fig. 8 C and 8D and Fig. 9 A and 9B.

The present embodiment is favourable, constructs because can be easy to form the surface of this orientation control element by the exposure device (for example substep projection mask aligner) that use has conventional resolution (1 a μ m or littler).

In the present embodiment, the pre-dumping (tilt angle, pre-dumping direction) of giving liquid crystal layer depends on the shape of the element characteristic of orientation control element.In order to produce pre-dumping, following two conditions are satisfied in the shape of preferred cell feature and arrangement.

The first, each bottom surface that is surrounded by immediate element characteristic must not have rotation axes of symmetry on the substrate normal direction.Because pre-dumping has directivity, if the bottom surface has rotation axes of symmetry (as in the situation of circle or equilateral triangle) on the substrate normal direction, then pre-dumping on the positive dirction and the pre-dumping on the negative direction will all equate for any given tilt angle.In other words, the pre-dumping on the different pre-dumping directions cancels each other out and balances, so that the liquid crystal molecule in the liquid crystal layer has 0 ° tilt angle generally.

The shape of each cylindrical unit feature upper surface itself can be the shape (for example isosceles triangle or trapezoidal) that does not have rotation axes of symmetry on the substrate normal direction.In this case, an advantage is arranged, can be by the bottom surface that obtains to satisfy aforementioned condition with simple relatively mode arrangement units feature.

The second, height (cup depth) H of orientation control element each element characteristic must be about 0.5 times or bigger of element characteristic spacing P, as in the situation of other embodiment.If the height H of element characteristic is less than about 0.5 times of spacing P, liquid crystal aligning can be balanced, and describes as reference Fig. 7 A, thereby makes the very difficult pre-dumping that obtains.

The preferred orientation control element that satisfies top two conditions for example can be based on the orientation control element 40 of triangular prism, as shown in Fig. 8 C and 8D.Perhaps, the orientation control element can have the arbitrary structures that Figure 16 A lists in the 16D.In the structure shown in Figure 16 A, on the surface of substrate 81, be arranged with the triangular prism shape element characteristic 82 that has the interval therebetween.In the structure shown in Figure 16 B, each element characteristic all is the quadrangular prism with trapezoidal upper surface.In the structure shown in Figure 16 C, to be different from the arranged in patterns triangular prism shape element characteristic shown in Fig. 8 C and Figure 16 A.In the structure shown in Figure 16 D, each element characteristic all is five jiaos of prisms.In any one of these structures, each element characteristic needn't be for axisymmetric.

Use arbitrary said structure, all can tilt angle and pre-dumping direction freely be set by the shape and/or the arrangement of control module feature.The shape of the mask that can use based on when exposure changes the shape and/or the arrangement of element characteristic at an easy rate, and is as described below.Therefore, an advantage is arranged, i.e. the selection of tilt angle and pre-dumping direction is not subjected to the restriction of manufacturing process.

Afterwards, as an example, the method for the orientation control element of making the present embodiment will be described at the orientation control element 80 shown in Figure 16 A.

At first, go up and form photoresist layers (thickness: for example 0.8 μ m) by being spin-coated on substrate 81 surface.Here, be formed with the glass substrate of conducting film on its surface as substrate 81.For example THMR-IP3300 is as photoresist.

Next, be generally used for making the shape of the exposure device processing resist layer of liquid crystal display device by use, thereby form the triangular prism of as shown in Figure 16 A, arranging (element characteristic) 82.More particularly, mask is set will become the zone on the resist layer surface of element characteristic 82 upper surfaces, and pass through this mask exposure resist layer with covering.Carry out the development of resist layer afterwards.

Then, vertical alignment layer is coated on the surface of substrate exposure.Thereby finished orientation control element 80.

By changing the shape will be used for the step of exposure mask, can be by forming any other orientation control element (for example Figure 16 B is to the orientation control element shown in the 16D) with top similar methods.

As mentioned above, the present invention's surface structure of being orientated control element must have two-dimentional anisotropic.Specifically, preferably different along X at least with the cycle of Y direction (supposing that these directions are perpendicular to one another), or along these direction generation phase change.Afterwards, with reference to Figure 16 A and 16C anisotropic according to orientation control element of the present invention is described.

As shown in Figure 16 A and 16C, be parallel to substrate 81 and be defined as directions X, and be parallel to substrate 81 and be defined as the Y direction perpendicular to the direction of directions X perpendicular to the direction of the pre-dumping direction that produces owing to the disclination in the gap between element characteristic (depression).

In the structure shown in Figure 16 A, if each some place on the Y direction obtains along the xsect of the orientation control element 80 of directions X, then moving along directions X with the spacing that equals 1/2 period T x will appear in each shape of cross section, and element characteristic 82 is provided with described period T x along directions X.Moving also can appear in the shape of cross section along the Y direction at each some place on directions X.In other words, element characteristic 82 so is provided with, and the phase change of shape of cross section promptly occurs along X and Y direction.In this case, can equate with period T y or different along the period T x of the element characteristic 82 of directions X along the element characteristic 82 of Y direction.Structure shown in Figure 16 B also is a same case.

On the other hand, in the structure shown in Figure 16 C, can not change, and can not change at the difference place on directions X along the phase place of Y direction shape of cross section at the difference place on the Y direction along the phase place of directions X shape of cross section.In this case, preferably be not equal to along the period T y of the element characteristic 82 of Y direction along the period T x of the element characteristic 82 of directions X.Structure shown in Figure 16 D also is a same case.

(embodiment 3)

Afterwards, with the liquid crystal display device of describing according to embodiment of the present invention 3.The liquid crystal display device of the present embodiment has the structure similar to the embodiment described with reference to Figure 11 A and 11B 1, and the device of the present embodiment that different is is to use the MVA mode liquid crystal display device of the orientation control element that is split into the zone.

As previously described, in order to improve the visual angle in the VAN pattern, preferably in each pixel, there is different pre-dumping direction (MVA pattern).According to the present invention, can be based on the lip-deep concavo-convex pre-dumping direction that is provided with arbitrarily that contacts with liquid crystal layer, the therefore relatively easy MVA pattern that realizes.

With reference to Figure 17 and 18 exemplary configurations that the present invention is orientated control element is described.

As shown in Figure 17 A, the substrate of the orientation control area 92 of 60mm * 60mm (for example quartz substrate) upward forms the orientation control element for example having.In orientation control area 92, each unit area 90 that all has 300 μ m * 100 μ m sizes is arranged in 200 * 600 array.Viewing area corresponding to display device is provided with orientation control area 92, and corresponding to each pixel of display device each unit area 90 is set.

As shown in Figure 17 B, each unit area 90 is all halved on vertical and horizontal, thereby forms four " son " zone 94.Each subregion 94 is all corresponding to a sub-pixel forming pixel.In each subregion 94, arrange a plurality of element characteristics.These element characteristics can have the shape of any element characteristic of describing in embodiment 1 and 2.Element characteristic in subregion 94 is arranged in such a way, gives pre-dumping on the different directions promptly for each different subregion.

With reference to Figure 18 A and 18B, will the arrangement of element characteristic in each subregion 94 be described more specifically.

Element characteristic 96 shown in Figure 18 A is similar to the element characteristic of the embodiment of for example describing with reference to Figure 12 1.Although each element characteristic 96 is shown as the xsect (W=0) with general triangular, it can select to have tetragonal xsect.Arrange the element characteristic 96 in each subregion 94, to be created in the pre-dumping on the direction of arrow.In this example, so design subregion 94, i.e. the direction (directions X among Figure 12 A) of element characteristic arrangement has been formed 90 ° angle with the described direction in each adjacent subarea territory 94.Thereby, give pre-dumping on the different directions can for each different subregion.

Element characteristic 96 ' shown in Figure 18 B is similar to the element characteristic of for example embodiment 2.Although each element characteristic 96 ' is exemplified as triangular prism, it selectively is five jiaos of prismatic or any other shapes.In the figure, also arrange the element characteristic 96 ' in each subregion 94, on the direction of arrow, to produce pre-dumping.

By like this each unit area 90 being divided into four sub regions 94, can realize that quadruple orientation cuts apart.When by use orientation control element 90 structure display devices, can use another orientation control element of being divided into similar area as with the relative substrate of orientation control element 90, maybe can use to be coated with the smooth of vertical alignment layer on its surface and to set off by contrast at the end.Yet in the situation of using smooth subtend substrate, roughly be halved owing to the tilt angle that is orientated control element 90; Therefore must design be orientated the concavo-convex of control element 90, to produce corresponding bigger tilt angle.

(thickness: about 1 μ m or bigger) orientation control element 90 is made in fluctuating to make the photoresist layer by mask exposure device (substep projection mask aligner).Selectively, as in aforesaid embodiment, can be by using the photoresist layer for example interfere exposure device or beamwriter lithography device to make arbitrarily to be formed on the substrate surface (thickness: about 1 μ m or littler) rise and fall and make orientation control element 90.

The orientation control element of the present embodiment is not limited to the structure shown in Figure 18 A and the 18B, as long as the pre-dumping direction that is produced by each concavo-convex element characteristic is to be scheduled to according to the particular location of this element characteristic on substrate surface.Each unit area 90 can be divided into the strip-shaped sub-regions territory.Other method of cutting apart unit area 90 has been described among Figure 19 A, 19B and the 19C.Selectively, each unit area 90 is not divided into subregion, can realizes being orientated by the orientation that changes element characteristic 96 or 96 ' according to the particular location on unit area 90 and cut apart.For example, arrangement units feature 96 or 96 ' like this, i.e. so-called continuous runner (pinwheel) orientation has been formed in the variation of the pre-dumping direction in each unit area 90.In addition, the quantity of the size of unit area 90, subregion and shape etc. can be provided with arbitrarily.The size in preferred unit zone 90 is corresponding to the size of each pixel in the display device.Element characteristic 96 or 96 ' size and spacing are being provided with arbitrarily.

(embodiment 4)

Afterwards, the method for making according to the orientation control element of embodiment of the present invention 4 is described with reference to the accompanying drawings.The difference of the present embodiment and embodiment 1 to 3 is to be orientated control element and has the surface that forms by impression.

In embodiment 1 to 3,, resin bed (photoresist layer) formed the orientation control element by being risen and fallen.According to this method, require resin bed to have sufficiently high photosensitivity, thereby thermal impedance and dissolubility resistent are proposed restriction with the support high resolving power.Because can not freely select the material of resin bed, so limited the electrology characteristic of resin bed material, for example specific inductive capacity, conductivity and impurity concentration.This can cause a problem in the manufacturing process, promptly for example when vertical alignment layer being coated to the processed resin layer surface of its shape, must select the solvent and the baking temperature of vertical alignment layer, so that do not damage resin layer surface.In addition, because the inside towards liquid crystal layer forms the concavo-convex of about 1 μ m height on resin layer surface, so can from resin bed, elution go out by concavo-convex meeting generation voltage drop or impurity.

In the present embodiment, on the orientation control element, form concavo-convex by imprint process.In this manual, this formation method is called " reproduction technology ".

The summary of this reproduction technology is described with reference to Figure 20 A and 20B.At first, as shown in Figure 20 A, make its surface and go up the irregular mother matrix 101 of formation.On the other hand, preparation substrate 102 has applied on its surface or has dripped the resin material 103 that is used to duplicate.Next, mother matrix 101 is pressed to the surface of substrate 102, be impressed on the resin material 103 with surface structure with mother matrix 101.Therefore, as shown in Figure 20 B, obtained to have orientation control element 105 corresponding to the concavo-convex resin bed 103 ' of mother matrix 101.

According to this reproduction technology, resin bed needn't have better photosensitivity, so can select the resin bed material with bigger degree of freedom.As a result, can obtain the display device of high-performance and high reliability.

Afterwards, the method that is orientated control element according to the manufacturing of the present embodiment is more specifically described with reference to the accompanying drawings.

At first, as shown in Figure 21 A, make mother matrix 101 with contoured surface.Can be by after forming the photoresist layer on the substrate, use two-beam interference exposure device, beamwriter lithography device or mask exposure device (substep projection mask aligner) graphically this photoresist layer to make mother matrix 101.What be used for that the method for graphical photoresist layer and for example embodiment 1 or 2 describe is the same.Selectively, can make mother matrix 101 by substrate or etching that Al or other material constitute such as the single crystalline substrate of Si substrate by mechanical lapping.Mother matrix 101 needs not to be optically transparent, but can be formed by any material that allows micromachining.Material as allowing micromachining for example can use high-resolution resist.

Next, as shown in Figure 21 B, resin material 103 is coated on the surface of transparent substrates 102, and afterwards mother matrix 101 is attached on the transparent substrates 102 in the mode that the concavo-convex and resin material 103 of mother matrix 101 contacts.As transparent substrates 102, can use the glass substrate that has conducting film (ITO) on glass substrate for example or its surface.As resin material 103, use UV (ultraviolet ray) cured resin here.Selectively, resin material 103 can be made up of other any resin material (as thermoplastic resin or thermosetting resin).

For example can transparent substrates 102 be attached to mother matrix 101 by using the device shown in Figure 22.Transparent substrates 102 is placed on the low platform (sample stage of being made by quartz glass) 107, and mother matrix 101 is placed on the high platform (sample stage of being made by quartz glass) 109.By reducing high platform 109, mother matrix 101 and transparent substrates 102 are linked together by resin material 103.

After mother matrix 101 and transparent substrates 102 link together, as shown in Figure 21 C, keep the preset time sections at the substrate 102 that when the direction of arrow is exerted pressure, posts mother matrix 101 on it.Afterwards, by using UV-lamp 106 usefulness ultraviolet ray irradiation resin material 103.Thereby resin material 103 is cured, and becomes and be resin bed 103 '.Can see through in the ultraviolet situation at substrate 102 and mother matrix 101, preferred not only from the surface of substrate 102 but also from its back side illuminaton ultraviolet ray.By carry out the ultraviolet ray irradiation like this from the substrate both sides, can shorten set time, even being substrate 102, extra advantage is provided with TFT and/or metal line, ultraviolet ray also unlikely casts a shadow.

Next, as shown in Figure 21 D, promote high platform 109, to take away mother matrix 101 from substrate 102.As a result, can obtain to have the orientation control element 105 of the resin bed 103 ' of fluctuating.

Above being not limited to according to the method for the manufacturing of the present embodiment orientation control element.For example can make roller shape mother matrix, the structure of roller shape mother matrix side is impressed on the resin bed.For example can carry out this impression by using the device shown in Figure 23.The object lesson of this method for stamping will be explained below.

At first, substrate 102 is placed on the platform 108 shown in Figure 23.Resin material 103 is coated on the surface of substrate 102.Here, resin material 103 is the UV cured resin.Next press substrate 102 along the roller shape mother matrix 110 of arrow 111 directions rotation, platform 108 moves along the direction of arrow 112 simultaneously.As a result, the part of the resin material 103 of being pressed by mother matrix 110 can be used opening 114 irradiations of ultraviolet ray by allowing UV radiation from UV-lamp 113.Thereby by shining resin material 103 with this linear mode with ultraviolet ray, resin material 103 solidifies continuously, has formed the resin bed 103 ' that rises and falls thus.

Use to the method that 21D describes, must prepare the roughly the same sheet mother matrix 101 of substrate 102 that has and be orientated control element 105 with reference to Figure 21 A.Therefore, in the situation of using large tracts of land substrate 102--in as the situation of on single big substrate, making a plurality of panels simultaneously (many substrate processing)--, make mother matrix 101 and become very difficult.Although can impress repeatedly less than the mother matrix 101 of substrate 102 by using size, location in this case will be very difficult.On the other hand, use the said method of roller shape mother matrix 110, in case make mother matrix 110 corresponding to single panel, even in the situation of many substrate processing, also can carry out continuous embossed to entire substrate 102.Thereby, an advantage is arranged, promptly can reduce the area of mother matrix 110.

In addition, by using roller shape mother matrix 110, for example can impress processing to thermoplastic resin (resin material that is used to duplicate) 103.Specifically, press on the thermoplastic resin 103 earlier with substrate 102 and thermoplastic resin 103 heating, and with mother matrix 110.Afterwards, make thermoplastic resin 103 cooling curings.For the imprint process of this thermoplastic resin 103, can use the device shown in the Figure 23 that is added with the heating and cooling device on it.

By using high viscosity resin, can use side surface configurations with the similar method impression of intaglio printing (perhaps transfer printing) roller shape mother matrix 110 as resin material 103.For this imprint process, for example can use the device shown in Figure 24.To explain the object lesson of this method for stamping below.

At first, substrate 102 is placed on the platform 123.Then, resin material 103 is placed in the container 120.Resin material 103 constantly discharges by the opening in container 120 bottom surfaces, and on the surface that will be coated to applicator roll 121, applicator roll 121 rotates on the direction of arrow 124.The resin material 103 that is coated to applicator roll 121 is applied to the surface of mother matrix 110 equably, and mother matrix 110 rotates on the direction of arrow 125.Afterwards, the mother matrix 110 that is coated with resin material 103 on it is pressed to the substrate 102 that is placed on the platform 123.Platform 123 synchronously moves with the rotation of mother matrix 110 on arrow 126 directions.As a result, the resin material 103 that is coated to mother matrix 110 is stamped on the substrate 102, has formed the desired fine structures of being made up of resin material 103 thus on substrate 102.By ultraviolet ray irradiation or heating the resin material 103 that is transferred on the substrate 102 is solidified, thereby become resin bed 103 '.

In arbitrary said method, mother matrix directly is pressed onto on the substrate 102 (as glass substrate), and may repeatedly utilize again.Therefore, mother matrix may be scratched.If abrasive mother matrix is used for continuing impression, then scratch itself also is stamped.Therefore, a possible method is the surface of mother matrix to be constructed to be impressed on the film earlier, further is impressed on the resin material by using this film should construct as mother matrix then.Afterwards, described film will be called " imprint masters ".For this imprint process, for example can use the device shown in Figure 25.To explain the object lesson of this method for stamping below.

At first, substrate 102 is placed on the back side of platform 128.Next, the film of forming by the deformable material of heating (thickness: 0.5 μ m or bigger) 127 be arranged between mother matrix 110 and the pressure roller 129, thereby on film 127, form meticulous concavo-convex.This film 127 for example can be PET.Next, being included in resin material 103 in the container 120 is coated to thinly on it and forms on the irregular film 127.By peeling off roller 130, the resin material 103 that applies like this is transferred (impression) to the substrate 102 that is placed on platform 128 back sides.By ultraviolet ray irradiation or heating the resin material 103 that is transferred on the substrate 102 is solidified, thereby become resin bed 103 '.

Thereby the surface structure by film 127 imprint masters 110 can stop mother matrix 110 to damage by a plurality of impression operations.Notice, described that the mode by applicator roll is coated to film 127 with resin material 103 with reference to Figure 24.If necessary, can before being transferred to substrate 102, it resin material 103 that is coated to film 127 be cured to a certain degree by ultraviolet ray irradiation or heating.

(embodiment 5)

Afterwards, liquid crystal display device according to embodiment of the present invention 5 is described with reference to the accompanying drawings.The liquid crystal display device of the present embodiment is the MVA mode display part with the orientation control element that is divided into a plurality of subregions.

As describing in embodiment 3, the orientation control element has can be corresponding to a plurality of unit areas of display device pixel.In the situation that adopts the MVA pattern, each unit area all is divided into a plurality of subregions.Each subregion gives each sub-pixel different pre-dumpings.

According to one of following preferred pattern, each unit area of the orientation control element of the present embodiment is divided into a plurality of subregions.Note the following mother matrix that pattern also can be used for embodiment 4, perhaps the orientation control element of embodiment 1 to 3 cut apart of orientation control element.

The first, in a single day as describing, in the VAN pattern, apply voltage with reference to Fig. 2 B, liquid crystal molecule just tilts, thus because their birefringence realizes white show state.Because liquid crystal cells is clipped in a pair of absorption axes each other between at an angle of 90 the polarizer 10, thus the absorption axes of the direction (pre-dumping direction) of preferred liquid crystal molecules tilt and each polarizer 10 angle at 45 on substrate surface respectively, effectively to utilize birefringence.

The second, the quantity (cutting apart quantity) of subregion is two or four in the preferred single unit area, and each subregion area equates.Notice that the subregion in only preferred each specified pixel equates.The area of the subregion in pixel can be different from the area of subregion in the one other pixel.

The pattern of may cutting apart of the unit area of first and second conditions is that wherein unit area is divided into for example pattern of Figure 19 A to four sub regions (I) shown in the 19C to (IV) above satisfying.

Any this cutting apart on one or two of a pair of relative substrate of display device that pattern can be applied to accompany liquid crystal layer therebetween.To 26C this exemplary application of cutting apart pattern is described now with reference to Figure 26 A.

Each has all illustrated corresponding to the part of the liquid crystal layer 142 of the single pixel of display device and the part of a pair of substrate 141 and 143 Figure 26 A to 26C.Be provided with vertical alignment-type liquid crystal layer 142 between first substrate 143 and second substrate 141.Generally speaking, first substrate 143 is color filter substrates, and second substrate 141 is TFT substrates.Yet, because it is concavo-convex to use similar methods form on each substrate, so can select second substrate 141 can be the TFT substrate for the color filter substrate and first substrate 143.In first substrate 143 of facing liquid crystal layer and second substrate 141, on the face of each, form concavo-convex with the identical or different pattern of cutting apart.Perhaps, can be only on the surface of a substrate, form and have concavo-convex that specific pattern cuts apart.

In the example shown in Figure 26 A, form concavo-convex on the surface of each in first substrate 143 and second substrate 141.These substrates 143 and 141 unit area have subregion (I) respectively and arrive (IV ') to (IV) and subregion (I '), and this is to cut apart according to the pattern shown in Figure 19 B.Therefore, pixel is divided into by relative subregion (I) and (I '); (II) and (II '); (III) and (III '); And (IV) and (IV ') four sub-pixels limiting.Thereby, can obtain the most stable orientation by using the identical pattern of cutting apart to substrate 141 and 143.Because tilt angle and concavo-convex relation are clearly, rise and fall so be easy to design.

In the example shown in Figure 26 B, only on the surface of second substrate 141, form and have concavo-convex to (IV) of the subregion (I) cut apart according to the pattern shown in Figure 19 B.The unit area of first substrate 143 (V ') have smooth surface, this structure can not produce pre-dumping.Therefore, each pixel is divided into four sub-pixels that limited by subregion (I) to (IV) and unit area (V ').In this example, only on a substrate 141, form to have and cut apart the concavo-convex of pattern, and formation is concavo-convex on another substrate 143, so shortened manufacturing process.Yet notice, suppose that concavo-convex the same on first and second substrates 141 and 143 shown in the concavo-convex and Figure 26 A on second substrate 141, the tilt angle of then giving central element in the liquid crystal layer 142 will be half of tilt angle of giving the central element in the liquid crystal layer 142 shown in Figure 26 A.

In the example shown in Figure 26 A and the 26B, on the surface of the substrate that contacts with liquid crystal layer, form according to the pattern shown in Figure 19 B cut apart concavo-convex.Perhaps, can form according to the pattern shown in Figure 19 A or the 19C or any other pattern cut apart as an alternative concavo-convex.

In the example shown in Figure 26 C, form concavo-convexly on the surface of each in first substrate 143 and second substrate 141, wherein substrate 143 and 141 unit area are divided into two sub regions (III ') and (IV ') and two sub regions (I) and (II) respectively.Yet the subregion of first substrate 143 is offset 1/2 subregion spacing from the subregion of second substrate 141, and accompanies liquid crystal layer 142 therebetween.For example, subregion (II) and two sub regions (III ') and (IV ') are relative.In this case, pixel is divided into by subregion (I) and (III '); Subregion (II) and (III '); Subregion (II) and (IV '); And four sub-pixels limiting of subregion (I) and (IV ').In this example, the area of each subregion (I), (II), (III ') and (IV ') is the twice of each the subregion area shown in Figure 26 A.Even in can only situation, in this example, also can fully make first substrate 143 and second substrate 141 therefore, with low relatively resolution cut zone.

Can realize that at Figure 26 A orientation cuts apart in any example shown in the 26C.Yet, consider manufacturing process, preferably only on a substrate, be provided with concavo-convex, as shown in Figure 26 B.Reason is that as mentioned above, small concavo-convex formation may make the manufacturing process of display device become complicated.

The measured value that uses its limit all up to one meter or bigger big substrate make in the situation of liquid crystal panel, the reproduction technology of describing in the embodiment 4 is particularly suitable for being used for the concavo-convex formation of liquid crystal aligning control, wherein makes the mother matrix that is impressed into substrate surface.Yet with respect to the substrate orientation mother matrix is very difficult, and therefore expectation does not need the pattern of cutting apart of hi-Fix.

Afterwards, need be when the surface structure with mother matrix is impressed into substrate surface with describing with respect to the pattern of cutting apart of substrate hi-Fix.

The pattern of cutting apart that is used for MVA pattern unit area must be such, be that each pixel all is split into accurately identical subregion of area so that when direction of observation last/down/right side/left in any direction brightness variation that will produce same amount when tilting.Yet, as long as the subregion area equates that the position of subregion and their tab order just can not influence demonstration.Therefore, it is favourable forming continuously the subregion (subregion group) of group on mother matrix, and wherein the size of chooser zone and unit area makes a unit area comprise a plurality of subregions.Preferably, the total area of the subregion of a sub regions group is substantially equal to the total area of the subregion of another subregion group.Thus, can guarantee that even after being impressed into mother matrix structure on the substrate, the total area that is included in the subregion in each unit area (pixel) on the substrate and does not need high-precision location about equally.

Afterwards, will describe by using the structure of the illustrative liquid crystal display part that the mother matrix that is arranged with the subregion group on it makes.Each liquid crystal display device all comprises the pixel of a plurality of matrixes that are arranged in rows and columns.Usually, gate line and CS line are arranged on the line direction, and source electrode line is arranged on the column direction.In the example below, the TFT substrate of liquid crystal display device has the orientation control structure (concavo-convex) of using aforementioned mother matrix to form.

Figure 27 A is the amplification view that shows three pixels of active-matrix liquid crystal display device of general type.Figure 27 B is the skeleton view of the pixel of liquid crystal display device shown in the displayed map 27A.For the sake of simplicity, suppose that here each pixel all has the rectangular shape that stretches on column direction.

As shown in Figure 27 B, each pixel all comprises following part: TFT substrate 910; Color filter substrate 911; And be clipped in liquid crystal layer 908 between substrate 910 and 911.In the face of on the face of liquid crystal layer, form transparency electrode 905 at color filter substrate 911.Face on the face of liquid crystal layer, at TFT substrate 910 for each pixel is provided with pixel electrode 906 and on-off element (TFT) 903.On-off element 903 links to each other with source electrode line 902 with gate line 901.The middle part that strides across each pixel is provided with CS line 904.As shown in Figure 27 A, the pixel region by its transmitted light has defined opening, is expressed as " 201 ".Therefore, be arranged in the concavo-convex function of showing the liquid crystal aligning control element most effectively of opening 201.In this example, opening is a rectangle, and has minor face that is parallel to line direction and the long limit that is parallel to column direction.

At first, will describe such example, wherein in opening 201, form concavo-convex to form the example in similar horizontal or vertical breach zone.In this case, do not carry out imprint step, can guarantee to realize being orientated to cut apart yet, because a plurality of subregion group is positioned at each opening 201 even between mother matrix and TFT substrate, do not carry out hi-Fix.Yet, may have following problem.

The minor face that is parallel to opening 201 in each breach, strip-shaped sub-regions territory or long limit.Therefore, the useful area (promptly to the contributive area of orientation control) with the subregion of the peripheral crossover of opening 201 is reduced by CS line 904 and gate line 901.As a result, the ratio between the total effective area of each sub regions may become uneven.In addition, the decrease of subregion useful area will depend on the gap Ws of adjacent apertures.Therefore, in order to alleviate the imbalance of area ratio, must be along perpendicular to subregion direction longitudinally, accurately locate border between the group of adjacent subarea territory with respect to the limit of each subregion that is parallel to longitudinal extension (in the opening).Although unbalanced degree will diminish along with reducing of each strip-shaped sub-regions field width degree, it is little that described width can not be done infinitely; For example, have the concavo-convex of about 1 μ m spacing, the width of each subregion about 10 μ m or bigger that will have nothing for it but in order to form.

Next, will the exemplary configurations shown in Figure 28 be described.In this example, form the orientation control structure, this orientation control structure is split into the strip region that tilts to pass through opening 201.Thereby, can significantly improve the ratio between each sub regions total effective area.

More preferably, guarantee that the subregion (I) owing to the space between adjacent apertures reduces is equal basically to the useful area of (IV).As a result, the total effective area of each sub regions can equate basically in the opening 201.A this object lesson cutting apart pattern has been described.

As shown in Figure 28, so form pixel, i.e. the height H of opening 201 _pBe A/F W _pIntegral multiple (equation (1)).

H _p=nW _p(wherein n is the integer except that 0) ... equation (1)

Suppose each subregion vertically and the angle between opening 201 minor faces be α, and the spacing of each subregion group is GP on the mother matrix, if equation (2) and equation (3) below angle [alpha] and spacing GP satisfy then can improve the imbalance between each sub regions total effective area.

Tan α=W _p/ (H _p/ n) ... equation (2)

GP=W _p/ m (wherein m is the integer except that 0) ... equation (3)

From top equation (2), angle [alpha] is 45 °.Suppose that m in the equation (3) is for example " 1 ", then can be by setting Pixel Dimensions (H _p, W _p) and the spacing GP of sub-pixel group satisfy equation (1 ') and equation (3 '), and impression to make angle [alpha] be 45 °, then no matter master pattern and will impress any mispointing between the concavo-convex substrate on it, always the total area of each sub regions can equate.In addition, no matter stride across the location and the width W cs of the CS line 904 at pixel middle part, and between the neighbor opening gap Ws size how, it is equal that the ratio between the subregion useful area can keep.

H _p=nW _p(wherein n is the integer except that 0) ... equation (1 ')

GP=W _p... equation (3 ')

Afterwards, will the worked example of the present embodiment display device be described.

＜example 1 〉

Display device according to example 1 comprises: first and second substrates, and each all has the orientation control structure that is split into zone shown in Figure 26 A; And be clipped in described liquid crystal layer between the substrate.Form orientation control structure on first and second substrate surfaces by the reproduction technology of describing to 21D with reference to Figure 21 A.

Afterwards, will the method for the display device of making example 1 be described more specifically.

At first, manufacturing has the concavo-convex mother matrix of being made up of a plurality of element characteristics.By using the resist be coated on the glass substrate to form concavo-convex on the mother matrix in the following manner: make resin through four exposures by using photomask, at each subregion, develop then at every turn.Expose when exposure directions is changed 90 ° for each subregion.Carry out the exposure of each subregion with following two steps.For example, can use the two-beam interference exposure device to expose (first exposure), can carry out conventional mask exposure (second exposure) afterwards.In order to form the purpose of a plurality of grooves on perpendicular to the direction of element characteristic orientation, carry out second exposure.Produce groove by mask exposure, because their spacing is coarse relatively.Forming with little spacing in the situation of groove, can in second exposure, use the two-beam interference exposure device being different from the direction of first exposure directions and interfere exposure.Replace carrying out the first and second top exposures, can also use the interference exposure device that wherein is not equipped with prism, and with the resists on the different laser beam while radiant glass substrate of two bundles.In this case, can control the interference fringe that produces by each laser beam independently.

Those of description are similar in final concavo-convex element characteristic and the embodiment 1.This element characteristic has the spacing P of 0.5 μ m; The width W in gap is 0 between the adjacent cells feature; The height H of each element characteristic is 0.5 μ m; Sidewall angles A and B are respectively 105 ° and 75 °; Upper surface width F is 0.Along forming groove perpendicular to the direction of element characteristic orientation with the spacing PG of 5 μ m, each groove part has the width G of 1 μ m.Be to be understood that, above-mentioned parameter P, W, H, A, B, F, PG, the value of G all is similar to.

Next, the surface structure with final mother matrix is impressed into substrate surface.By using the device shown in Figure 22 to carry out described impression.Specifically, with 35Kg/cm ²Pressure mother matrix is pressed on have the UV cured resin substrate of (1 μ m), keep-uped pressure 60 seconds, described UV cured resin is coated on the substrate by spin coating.After pressing, with ultraviolet ray (0.7J/cm ²) radiation UV cured resin, the UV cured resin solidifies thus, and becomes the upward concavo-convex resin bed of formation of its surface.Afterwards, mother matrix is removed from substrate.

Then, form vertical alignment layer on the resin layer surface by being spin-coated on.As a result, obtained first substrate.Also make second substrate by similar method.

Thus obtained first and second substrates are so placed, promptly as shown in Figure 26 A toward each other, vertical alignment layer is inwardly faced, and links together, and leaves simultaneously the gap of 3 μ m betwixt.Between these substrates, inject liquid crystal (MLC6609) with negative Δ ε.Thereby, finished the display device of example 1.

By the liquid crystal aligning in the display device of checking example 1, can determine that central element is vertical orientated when striding across liquid crystal layer and do not apply voltage, from the substrate normal direction one tilt (pre-dumping) arranged.Can also determine that when striding across liquid crystal layer and apply voltage, liquid crystal aligning is divided into four zones, wherein liquid crystal molecule tilts in each different direction, as shown in fig. 1.

Although example 1 illustrated by utilizing the two-beam interference exposure to wait to make the situation of mother matrix, can also by manufacturing have to embodiment 1 and 2 in mother matrix by the similar element characteristic of the element characteristic that uses formation such as beamwriter lithography device, substep projection mask aligner obtain to example 1 in similar effect.

＜example 2 〉

Display device according to example 2 comprises: first and second substrates, and each all is formed with the orientation control structure in its surface; And be clipped in liquid crystal layer between the substrate.As shown in Figure 28, each orientation control structure all is divided into along the upwardly extending a plurality of subregion groups in side of tilt with respect to each opening (α=45 °).Each subregion group is all formed by four sub regions (I), (II), (III) with (IV).In this display device, set Pixel Dimensions (width W _p, height H _p) and the spacing GP of subregion group equation (1 ') and the equation (3 ') above satisfying.In other words, the height H of each pixel _pIt is width W _pThree times (n=3), the spacing GP of subregion group equals the width W of each pixel _p(m=1).

The reproduction technology of describing to 21D by reference Figure 21 A forms concavo-convex on first and second substrate surfaces.

Afterwards, the method for the display device of making example 2 will be specifically described.

At first, manufacturing has the concavo-convex mother matrix of being made up of a plurality of element characteristics.By using two-beam interference exposure and mask exposure, use with example 1 in the similar methods used form concavo-convex on the mother matrix.In the present example, as shown in Figure 28, with the arrangement setting that repeats by subregion (I), (II), (III) and the subregion group (spacing GP:100 μ) (IV) formed.The direction of element characteristic is so stipulated in each subregion, makes because there is constant pre-dumping direction in concavo-convex in each subregion, and differs from 90 ° by the pre-dumping direction of concavo-convex generation in the adjacent subarea territory on substrate surface.Element characteristic in each subregion is similar to embodiment 1.These element characteristics have the spacing P of 0.5 μ m; The width W in gap is 0 between the adjacent cells feature; The height H of each element characteristic is 0.5 μ m; Sidewall angles A and B are respectively 105 ° and 75 °; Upper surface width F is 0.Along forming groove perpendicular to the direction of element characteristic orientation with the spacing PG of 5 μ m, each groove part has the width G of 1 μ m.

As second substrate, preparation TFT substrate as shown in Figure 23.On the TFT substrate, the width W of each pixel _pBe 100 μ m; The height of each pixel _HP is 300 μ m; The width W cs of every CS line is 20 μ m; The width Ws in the space between adjacent apertures is 30 μ m.

Next, the surface structure with final mother matrix is impressed into the TFT substrate surface.By using the device shown in Figure 22 to carry out described impression.Specifically, with 35Kg/cm ²Pressure mother matrix is pressed onto on have the UV cured resin substrate of (1 μ m), keep-uped pressure 60 seconds, described UV cured resin is coated on the substrate by spin coating.After pressing, with ultraviolet ray (0.7J/cm ²) radiation UV cured resin, the UV cured resin solidifies thus, and becomes its surface and go up to form and have concavo-convex resin bed.Afterwards, mother matrix is removed from substrate.

Then, on resin layer surface, form vertical alignment layer by rotary coating.As a result, obtained to be formed with on it TFT substrate of orientation control structure.Also set off by contrast at the end (first substrate) by similar method manufacturing.

Thus obtained first and second substrates are so placed, and make vertical alignment layer inwardly face ground toward each other, and link together, and leave the space of 3 μ m simultaneously betwixt.Between these substrates, inject liquid crystal (MLC6609) with negative Δ ε.Thereby, finished the display device of example 2.

By the liquid crystal aligning in the display device of checking example 2, can determine that central element is vertical orientated when not striding across liquid crystal layer and apply voltage, from the substrate normal direction one tilt (pre-dumping) arranged.Can also determine that when striding across liquid crystal layer and apply voltage, liquid crystal aligning is divided into four zones, wherein liquid crystal molecule tilts in each different direction.Because each sub regions (I) in each pixel is equal substantially to the total area of (IV), thus direction of observation last/down/when any direction in the right side/left side tilted, the brightness that has produced same amount changed, thereby outstanding viewing angle characteristic is provided.

Although example 2 illustrated by utilizing the two-beam interference exposure to wait to make the situation of mother matrix, can also by manufacturing have to embodiment 1 and 2 in mother matrix by the similar element characteristic of the element characteristic that uses formation such as beamwriter lithography device, substep projection mask aligner obtain to example 2 in similar effect.

(embodiment 6)

Afterwards, liquid crystal display device according to embodiment of the present invention 6 is described with reference to the accompanying drawings.The liquid crystal display device of the present embodiment is the MVA mode display part with orientation control element, wherein is orientated control element and is divided into a plurality of subregions.Yet the liquid crystal display device of the present embodiment is different from the liquid crystal display device of top any other embodiment, and difference is that each subregion further is split into a plurality of tiny areas.

In embodiment 5, the orientation that is used to realize different pre-dumping directions is cut apart by unit area (corresponding to pixel) is divided into subregion and is undertaken.On the other hand, according to the present embodiment, each subregion all is divided into a plurality of tiny areas, and each is all at equidirectional (pre-dumping direction) but with different angles (tilt angle) generation pre-dumping.Thereby, realized that a kind of orientation cuts apart, this orientation cut apart caused not only on the pre-dumping direction different and also on tilt angle different zone.

To the reason of further cutting apart each subregion with aforementioned manner be described.

Figure 29 is the figure that shows light transmission Tr when striding across liquid crystal layer and apply voltage V.As can be seen from Figure 29, along with the increase of tilt angle, transmissivity Tr moves towards low-voltage.This is because even supposition vergence direction (pre-dumping direction) is identical, the voltage that applies of response and depend on initial tilt angle in the trend that the polar angle direction tilts and change.

Therefore, by each sub-pixel under the MVA pattern being further divided into a plurality of tiny areas that are used to produce different tilt angles, in case apply voltage, liquid crystal layer will not only have the zone that liquid crystal molecule wherein tilts in different directions, but also has the zone that liquid crystal molecule (in identical direction, but) tilts with different angle (i.e. angle on the direction that liquid crystal molecule will rise).These zones are balanced, make in the brightness that when direction of observation changes, produces with contrast on any variation all than in the situation of routine slightly.Cut apart by such realization high precision orientation, can realize high-quality display.

Although traditionally after deliberation in each pixel, be used to produce the different orientation direction various orientations cut apart, but it is unprecedented cutting apart by the orientation that the present embodiment realizes, is to be positioned near having given different tilt angles along the liquid crystal molecule of thickness of liquid crystal layer direction mid-plane because give.The possible cause of this precedent is not that to form the orientation control structure very difficult by carry out orientation process with high precision more.

In the orientation control element of the present embodiment, each subregion all is divided into a plurality of tiny areas so that difform element characteristic is arranged in each different tiny area.

Figure 30 A and 30B are the skeleton view of explanation according to the exemplary subregion structure of the present embodiment.

Subregion 210 shown in Figure 30 A is divided into two tiny area 220a and 220b.In tiny area 220a and 220b, be arranged with element characteristic 212a and 212b with roughly the same spacing P respectively with triangular cross section.Tiny area 220a has realized identical pre-dumping direction with 220b.Yet the Sidewall angles 213a of each element characteristic 212a is less than the Sidewall angles 213b of each element characteristic 212b among the tiny area 220b among the tiny area 220a.Therefore, tiny area 220a has realized being different from the tilt angle of being realized by tiny area 220b.

Subregion 240 shown in Figure 30 B is divided into two tiny area 230a and 230b.In tiny area 230a and 230b, be arranged with the element characteristic 231a and the 231b of triangular prism shape respectively with roughly the same spacing P.The height that constitutes the isosceles triangle of each element characteristic 231a upper surface in tiny area 230a is different from the height that constitutes the isosceles triangle of each element characteristic 231b upper surface among the tiny area 230b.Although therefore tiny area 230a has realized identical pre-dumping direction with 230b, tiny area 230a has realized being different from the tilt angle of being realized by tiny area 230b.

The orientation control element of the present embodiment is made up of above-mentioned subregion.Figure 31 A is the figure of unit area representative configuration in the explanation orientation control element.

Unit area 250 shown in Figure 31 A is divided into four sub regions (I), (II), (III) and (IV).For example, each subregion all has the structure shown in Figure 30 A or the 30B.In other words, subregion (I) is divided into two tiny area Ia and Ib.Other subregion (II) to (IV) is divided into two tiny area IIa and IIb, IIIa and IIIb and IVa and IVb equally respectively.

In the example shown in Figure 31 A, the area ratio that is included between two tiny areas in each subregion is expressed as 1: 1.Yet notice that the area ratio between tiny area can be according to viewing angle characteristic optimization, and the tiny area area that is included in each subregion needn't equate.Unit area is divided into the pattern of subregion and each subregion is divided into those that the pattern of tiny area is not limited to list among Figure 31 A, but can select arbitrarily.

Can by with other embodiment in the similar methods used form the orientation control element of the present embodiment.Preferably, form the orientation control element of the present embodiment by reproduction technology.

Afterwards, will the worked example of the present embodiment liquid crystal display device be described.

＜example 3 〉

Liquid crystal display device according to example 3 comprises first and second substrates, and is clipped in the liquid crystal layer between these substrates.On second substrate (TFT substrate) surface, be provided for limiting the concavo-convex of liquid crystal aligning.First substrate (color filter substrate) has smooth surface.Concavo-convex on second substrate surface is such, and as shown in Figure 31 A, each unit area is divided into four sub regions (I) to (IV), and each subregion is further divided into two tiny area Ia and Ib, IIa and IIb, IIIa and IIIb and IVa and IVb.Subregion (I) equates to (IV) area.Area ratio Ia in each subregion between tiny area: Ib, IIa: IIb, IIIa: IIIb, IVa: IVb is 1: 4 entirely.

In each subregion, as shown in Figure 30 A, be arranged with element characteristic with triangular cross section.The spacing P of each element characteristic is 0.5 μ m; The width W in the gap between the adjacent cells feature is 0; The width F of upper surface is 0.In tiny area Ia, IIa, IIIa and IVa, the height H of each element characteristic and side wall angle A and B so stipulate, promptly has 89 ° inclination angle (being the angle that liquid crystal molecule will raise) at substrate and liquid crystal layer liquid crystal molecule at the interface.On the other hand, in tiny area Ib, IIb, IIIb and IVb, the height H of each element characteristic and side wall angle A and B so stipulate, promptly has 85 ° inclination angle at substrate and liquid crystal layer liquid crystal molecule at the interface.In addition, the spacing GP with 5 μ m is provided with groove on the direction perpendicular to the element characteristic orientation.The width of each groove is 1 μ m.

The liquid crystal display device of following manufacturing example 3.

At first, make and be formed with predetermined concavo-convex roller shape mother matrix on its surface, the surface structure of described mother matrix is impressed on the UV cured resin that is coated on the substrate surface.As a result, at the resin bed that has formed structure concavo-convex on having corresponding to mother matrix on the TFT substrate.By using the device shown in Figure 25 to carry out this impression.Afterwards, form vertical alignment layer on the resin layer surface by being spin-coated on.

Be formed with the color filter substrate that is formed with vertical alignment layer on the TFT substrate of resin bed and its surface on it and so place, promptly vertical alignment layer inwardly in the face of ground toward each other, and link together, leave the space of 3 μ m simultaneously betwixt.Between these substrates, inject liquid crystal (MLC6609) with negative Δ ε.Thereby finished the display device of example 3.

The measurement of each tiny area actual light transmissivity is described below.The axis of homology of polarizer is on vertical and horizontal direction.

Figure 31 B shows positive transmissivity, Figure 31 C show the tiny area Ia that when observing, obtains with 45 ° at position angle (in the upper right side upwards 45 °) and visual angle 60 ° (promptly from 60 ° of substrate normal directions) to IVa, reach the transmissivity of Ib to IVb.From these results as can be seen, by realizing as the high precision orientation of this example is cut apart, be balanced, thereby suppressed to depend on any variation of the brightness of direction of observation, obtained better viewing angle characteristic thus by the liquid crystal aligning of each tiny area generation.

(embodiment 7)

Afterwards, liquid crystal display device according to embodiment of the present invention 7 is described with reference to the accompanying drawings.

The liquid crystal display device of the present embodiment comprises a pair of relative substrate, and is clipped in the liquid crystal layer between them.Construct in a pair of substrate one or two by using the orientation control element 501 shown in Figure 32 A.

Orientation control element 501 comprises substrate 502 and is formed on substrate 502 lip-deep a plurality of element characteristics 503 that this orientation control element can be with acting on the orientation control device that controlling packet is contained in the liquid crystal molecular orientation in the liquid crystal layer 510.Liquid crystal layer 510 is the vertical alignment-type liquid crystal layers that wherein use minus nematic liquid crystal (Δ ε＜0).

Being formed on orientation control element 501 lip-deep each element characteristic 503 all is made up of wall part 505 and ramp portion 507.Wall part 505 comprises two side 505a and 505b and the ridge 505r that is formed by these sides.Form ramp portion 507 so that contact with a side 505a of wall part 505.Ramp portion 507 has the inclined-plane 507a with respect to the surface tilt of substrate 502.Wall part 505 and ramp portion 507 are made of different materials usually.Although the wall part 505 of Figure 32 A is depicted as the shape with general triangular xsect, wall part 505 can select to have the crooked shape of cross section or the shape of cross section of any other (for example quadrilateral).

Figure 32 B is the exemplary plan view of orientation control element 501.Orientation control element 501 comprises element characteristic 503, and it shows as the short relatively bar that (is called " Y " direction afterwards) arranges on the direction of ridge 505r, leaves predetermined groove 504 between bar.Element characteristic 503 is arranged along being parallel to the direction vertical with the Y direction (being called " X " direction later on).Although Figure 32 B shows directions X perpendicular to the Y direction, directions X can be any direction that is different from the Y direction.Notice that in the present embodiment, element characteristic 503 needn't periodic arrangement.

The inclined-plane 507a of mode description unit feature 503 that afterwards, will be by example applies the mode of orientation control for the liquid crystal molecule in the liquid crystal layer 510.

In not striding across the state that liquid crystal layer 510 applies voltage (being called " OFF " attitude afterwards), the major axis that is positioned at each liquid crystal molecule of 507a surface, inclined-plane is approximately perpendicular to each inclined-plane 507a orientation of orientation control element 501.Therefore, the liquid crystal molecule in the liquid crystal layer 510 is from substrate 502 normal to a surface directions inclinations (pre-dumping direction).When striding across liquid crystal layer 510 apply voltage on the direction perpendicular to substrate 502, each liquid crystal molecule will manage to tilt in described pre-dumping direction.If the voltage that applies is enough high, then the liquid crystal molecule surface that will be roughly parallel to substrate 502 lies low, and the major axis of liquid crystal molecule is arranged on the direction of groove 504.

Orientation control element 501 in order to ensure the present embodiment has enough liquid crystal aligning control abilities, and preferred cell feature 503 has 0.1 μ m or bigger average headway.On the other hand, for the whole surface control liquid crystal aligning direction by orientation control element 501, preferred cell feature 503 has 10 μ m or littler average headway.

In the present embodiment, " (on average) spacing of element characteristic " is defined as in the plane of substrate surface, with summit, side that associated ramp partly contacts between distance between the adjacent wall part that obtains.For example, the spacing of the element characteristic shown in Figure 33 A is the distance P x between the peak 505p of the side 505a of any two adjacent wall parts 505 of obtaining (side 505a contacts with the ramp portion 507 relevant with them) in the plane of substrate surface.Similarly, have in the situation of essentially rectangular xsect at each sidewall sections, as shown in Figure 33 B, the spacing of element characteristic is the distance P x between the peak 506p of side 506a of any two adjacent wall parts 506 of obtaining in the plane of substrate surface.

Spacing Py along the element characteristic 503 of ridge 505r direction for example is not less than 0.1 μ m, and is not more than 10 μ m.Each groove part has the width that for example is not less than 10nm, and it is equal to or less than along the spacing Px of directions X element characteristic 503.

In the present embodiment, preferred cell feature 503 has the height (being the height of wall part 505) that is not less than 10nm and is not more than 10 μ m here.If highly be not less than 10nm, the surface structure that then is orientated control element 501 can limit liquid crystal molecular orientation reliably.On the other hand, if highly be not more than 10 μ m, then can suppress the relevant any problem of net thickness with the liquid crystal layer 510 that changes by the existence of element characteristic 503.

For example can be greater than 0 ° and be not more than the inclined-plane 507a that selects each element characteristic 503 in 45 ° the scope arbitrarily and the angle between substrate 502 surfaces.For example, if the angle between each inclined-plane 507a and substrate 502 surfaces is not less than 10 ° and be not more than 45 °, then near the inclined-plane 507a of orientation control element 501, liquid crystal molecule can tilt be not less than 10 ° and be not more than 45 ° and be orientated from the normal direction of substrate 502.

Now, with reference to Figure 33 C and 33D, will describe " inclined-plane of each element characteristic and the angle between the substrate surface (this angle can simply be called afterwards ' angle of chamfer ') ".Because relevant with their manufacture method etc., the inclined-plane 507a of each ramp portion 507 of the present embodiment may not can become smooth, as shown in Figure 33 C and 33D.In this case, as shown in Figure 33 C and 33D, in the viewgraph of cross-section that obtains perpendicular to the ridge 505r of each element characteristic, between the peak 505p of wall part 505 side 505a (side 505a contacts with ramp portion 507) and some 507c that the inclined-plane 507a and the substrate surface of ramp portion 507 contact, be decorated with line 507A; And the angle a1 between this line 507A and substrate surface will be called " angle of chamfer ".

In the side of the wall part 505 of each element characteristic 503, not with the side 505b of ramp portion 507 contacts preferably and the surface of substrate 502 form a angle greater than the angle a1 between aforementioned inclined-plane 507a and substrate 502 surfaces.Angle between the side 505b of wall part 505 and the surface of substrate 502 is usually greater than 45 ° and less than 180 °.As shown in Figure 33 E, " angle between the side 505b of wall part 505 and the surface of substrate 502 " is defined as the angle a2 between substrate surface and the line 505B, and between the line 505B peak 505p ' that is drawn in wall part 505 side 505b and the some 505c that side 505b and substrate surface contact.

At the interface liquid crystal molecule is along orientation control element 501 normal to a surface directions orientation between orientation control element 501 and liquid crystal layer.In other words, be positioned at liquid crystal molecule on each inclined-plane and have pre-dumping (first pre-dumping), have along the pre-dumping (second pre-dumping) of the normal direction of the side 505b of wall part and be positioned at liquid crystal molecule on each wall part side along inclined-plane 507a normal direction.In the present embodiment, each element characteristic 503 has asymmetric xsect, is preponderated than the pre-dumping that the side 505b by wall part gives by the pre-dumping that inclined-plane 507a gives.Therefore, be positioned at influence,, and have the tilt angle littler than first pre-dumping so for example liquid crystal molecule will have the pre-dumping direction identical with first pre-dumping near first pre-dumping that more is subject to along the liquid crystal molecule of thickness of liquid crystal layer direction mid-plane give by inclined-plane 507a.Note, be positioned at the influences that not only are orientated control element 501 surface structures near liquid crystal molecule, but also be subjected to the influence that basal surface is constructed of setting off by contrast that contact with liquid crystal layer 510 upper surfaces along thickness of liquid crystal layer direction mid-plane.

Although the exposed surface of the element characteristic 503 of the orientation control element 501 shown in Figure 32 A contacts with liquid crystal layer 510, they there is no need to contact with each other.For example, between orientation control element 501 and liquid crystal layer 510, vertical alignment layer can be set and/or be used as to liquid crystal layer 510 apply voltage electrode function conducting film or have the multilayer film of pressing conducting film and alignment films sequential cascade.Any film that preferably is arranged between orientation control element 501 and the liquid crystal layer 510 is enough thin, so that described film can obtain to reflect the surface structure of element characteristic 503 (for example having 1 μ m or littler thickness) shape.Such film can make the orientation of the surface structure control liquid crystal layer 510 of orientation control element 501.

Afterwards, the illustrative methods of making orientation control element 501 is described with reference to the accompanying drawings.

Figure 34 A is the schematic cross section of explaining by the made orientation control element 501 that uses energy thermal deformation (hot-fluid) to 34E.

At first, as shown in Figure 34 A, on substrate 520, form wall part cambium layer 522 (thickness: for example 300 μ m).Although to the material of substrate 520 and wall part cambium layer 522 without limits, the present embodiment has illustrated quartz substrate as substrate 520, with the situation of silicon nitride film as wall part cambium layer 522.

Next, as shown in Figure 34 B, resist pattern 524 comprises by using negative resist for example to be formed on a plurality of islands part on the wall part cambium layer 522.Spacing along the island part of directions X resist pattern 524 will be according to the spacing of the wall part that will form, and promptly element characteristic spacing Px selects.In the present embodiment, are 1.6 μ m along the average headway of directions X resist pattern 524.Along Y direction perpendicular to directions X, the resist pattern 524 that comprises a plurality of islands part is set, the average space between the part of island is 0.8 μ m.Average headway along Y direction resist pattern 524 is 3.2 μ m.

Afterwards, as shown in Figure 34 C, by using resist pattern 524 as mask etching wall part cambium layer 522.For example, use buffered hydrofluoric acid to make wall part cambium layer (silicon nitride film) 522 experience wet etchings 60 seconds, water cleans well afterwards.By this etching, formed the wall part 526 that has corresponding to the height of wall part cambium layer 522 thickness.In Figure 34 C, the xsect of each wall part 526 all is depicted as the general triangular that the bottom surface contacts with substrate 520, and the shape of cross section of wall part 526 is not limited to the shape shown in Figure 34 C.The xsect of each wall part 526 can be have the base that contacts with substrate 520 trapezoidal.Selectively, by wall part cambium layer 522 is carried out anisotropic etching, can form each wall part that all has the essentially rectangular xsect 526.

Next, by after using acetone etc. to remove resist pattern 524, a plurality of ramp portion cambium layer 528 (Figure 34 D) on substrate 520, have been formed.Ramp portion cambium layer 528 is island parts of the resist pattern for example be made up of positive resist.Each island part of resist pattern 528 all so forms, promptly with a side 526a contact of corresponding wall part 526.In the present embodiment, form resist pattern 528 by using photomask, the pattern of the pattern shift 0.4 μ m of the photomask (reticle) that this photomask uses when having resist pattern 524 from form Figure 34 B.Therefore, are 1.6 μ m along the average headway of the adjacent island part of directions X resist pattern 528, the average space between the adjacent island part of resist pattern 528 is 0.8 μ m.

Afterwards, as shown in Figure 34 E, heating resist pattern 528 is so that 528 distortion of resist pattern form ramp portion 530 thus.For example can realize the formation of ramp portion 530 by heated substrate in hot baking box (temperature: 135 °) in 520 10 minutes.Temperature in the baking box can be not cause wall part 526 and substrate 520 distortion, but causes any temperature of the thermal deformation (hot-fluid) of resist pattern 528, and can select according to the material of wall part 526 and resist pattern 528.

Thereby, having obtained to have the orientation control element 600 of a plurality of element characteristics 532, each element characteristic 532 all is made up of wall part 526 and ramp portion 530.In thus obtained orientation control element 600, element characteristic 532 has the average headway of 1.6 μ m, and the inclined-plane 530a of each ramp portion 530 and substrate 502 are formed 12 ° angle.Each element characteristic 532 of the present embodiment all has the xsect of the general triangular shown in Fig. 4 E, and this triangle has 112 ° drift angle (being the angle between the inclined-plane 530a of the side 526b that exposes of each wall part and each ramp portion 530).

Although said method has caused the distortion of ramp portion cambium layer (resist pattern) 528 by hot-fluid, can also make the distortion of ramp portion cambium layer by exposure.

Afterwards, to 35E, will another method of making the present embodiment orientation control element be described with reference to Figure 35 A.In the method, make the ramp portion cambium layer form ramp portion by the canted exposure that utilizes wall part.

At first, as shown in Figure 35 A, for example form a plurality of wall parts 542 on the substrate 540 by being stamped in.In the present embodiment, (color is inlayed CK-2000 by using resin black (resin black); Fuji Hunt Electronics Technolgy K.K.) forms wall part 542.

Next, as shown in Figure 35 B, form ramp portion cambium layer 544, and cover any surface portion of the substrate 540 that does not form wall part 542 on it so that be filled between the adjacent wall part 542.Have the thickness identical with the height of wall part 542 although Figure 35 B shows ramp portion cambium layer 544, these two values also can be different.Ramp portion cambium layer 544 for example is by negative resist (OMR85; Tokyo Ohka Kogyo Co., the Ltd.) layer of Zu Chenging.

Afterwards, as shown in Figure 35 C, ramp portion cambium layer (negative resist layer) 544 is through canted exposure.Exposure directions can be selected according to the direction that will form the inclined-plane.As a result, the part of the negative resist layer 544 that is not only covered by wall part 542 is exposed.

At this moment, as shown in Figure 35 C, any surf zone of the substrate 540 except that the zone that will be exposed in this step covers with mask.In this case, after the step of Figure 35 C, any surf zone of the substrate 540 that has been exposed in the step shown in Figure 35 C covers with mask, and any zone of the negative resist layer 544 of mask of no use covering experiences from the exposure (Figure 35 D) of the direction that is different from the exposure directions shown in Figure 35 C.Like this,, can carry out repeatedly (can be three times or more times) canted exposure for the surface of given expectation structure, all have different exposure directions at every turn.Perhaps, by using transmittance substrate 540, can carry out the canted exposure that illustrates Figure 35 C and the 35D from the dorsal part of substrate 540.

By carry out the development of negative resist layer 544 after exposure, the part of the negative resist layer 544 that only will expose removes, and all has the ramp portion 546 of inclined-plane 546a so unexposed portion has formed each, as shown in Figure 35 E.Thereby, having obtained to have the orientation control element 601 of a plurality of element characteristics 548, each element characteristic 548 all is made up of wall part 542 and ramp portion 546.Notice that carrying out in the situation of repeatedly canted exposure shown in Figure 35 C and 35D, the inclined-plane of each element characteristic 548 all has the normal direction of the exposure directions that depends on element characteristic 548 experience in the change exposure directions.

In the method for describing to 34E and Figure 35 A to 35E, formed ramp portion by making the ramp portion cambium layer with reference to Figure 34 A.Yet ramp portion can not adopt any this deforming step to form.

Afterwards, to 36D, will another method of making the present embodiment orientation control element be described with reference to Figure 36 A.In the method, as stopping, form ramp portion for substrates coated solution with each wall part by ink-jet technology.Therefore, needn't carry out making in the method that Figure 34 A illustrates in to 34E and Figure 35 A to 35E the step of ramp portion cambium layer distortion.

At first, with reference to Figure 36 A, wait a plurality of wall parts 552 of formation on substrate 550 by impression.For example (OFPR800, Tokyo Ohka Kogyo Co. Ltd.) form wall part 552 by positive resist.The material of wall part 552 can be to have relatively little capillary any material, and needs not to be photosensitive.

Next, as shown in Figure 36 B, the substrate 550 that forms wall part 552 on it is carried out canted exposure, only allow a side 552a exposure of each wall part 552.As a result, give water wettability only for the side 552a of each sidewall sections 552, and the another side 552b of each sidewall sections 552 keep its water repellency.

At this moment, as shown in Figure 36 B, cover any surf zone of the substrate 550 will exposed areas except in this step with mask.In this case, after the step of Figure 36 B, any surf zone of the substrate 550 that has been exposed in the step shown in Figure 36 B covers with mask now, and the wall part in any zone of mask of no use covering 552 experiences from the exposure (Figure 36 C) of the direction that is different from the exposure directions shown in Figure 36 B.By carrying out repeatedly (can be three times or more times) canted exposure like this, all have different exposure directions at every turn, give water wettability can for any side of each wall part 552.Selectively, can carry out the canted exposure that illustrates Figure 36 B and the 36C from the dorsal part of substrate 550.

Afterwards, as shown in Figure 36 D, form the solution of ramp portion for the surface-coated of substrate 550 by using ink-jet technology for example.At this moment, the water repellency side 552b by each wall part 552 repels described solution, so that be attached to the surface of the water wettability side 552a and the substrate 550 of each wall part 552.Then, dry coated solution has formed each thus and has all had the ramp portion 554 of inclined-plane 554a.Although to the solution that forms ramp portion without limits, can use water wettability (water-dispersion type) printing ink, for example polyvinyl alcohol (PVA).

In the step of Figure 36 D, hydrophobicity (organic solvent type) printing ink is alternately as the solution that forms ramp portion.In this case, give lipophilicity (oleophilicity) must for the side 552a of wall part 552.That takes for the wettable that improves the solution that is used to form ramp portion gives water wettability or lipophilicity for wall part 552 side 552a can be expressed as and to give or strengthen lyophily.

By top method, obtained to have the orientation control element 602 of a plurality of element characteristics 556, each element characteristic 556 all is made up of wall part 552 and ramp portion 554.Notice, in the change exposure directions shown in Figure 36 B and 36C, carry out in the situation of repeatedly canted exposure that the inclined-plane 556a of each element characteristic 556 has the normal direction of the exposure directions that depends on element characteristic 548 experience.

Use Figure 34 A to 34E, Figure 35 A to 35E and the method that illustrates in the 36D of Figure 36 A, can make the whole surperficial orientation control element 600,601 and 602 of controlling the liquid crystal layer original alignment that can enoughly contact at an easy rate with liquid crystal layer.By utilizing orientation control element 600,601 or 602, an advantage is provided, promptly the orientation of liquid crystal layer can be controlled more equably.In addition, with top method, even reduced the average headway Px (for example a few μ m or littler) of the element characteristic of orientation control element, also can be arbitrarily and the angle between each inclined-plane and the substrate surface, the height of each wall part etc. accurately are set.Because can adjust angle between each inclined-plane and substrate surface at an easy rate, so can realize being difficult to the high pre-dumping that obtains with conventional method according to the spacing of wall part, height etc.

Selectively, form the orientation control element 501 shown in Figure 32 A by impression (reproduction technology).Afterwards, will method that make the orientation control element by impression be described.

At first, by with for example with reference to accompanying drawing 34A to 34E, 35A to 35E and 36A make the mother matrix that has a plurality of element characteristics on its surface to any method similar methods that 36D describes.

Next, by using this mother matrix, the surface structure of mother matrix is impressed on the layer (resin bed) etc. of resin material, thereby has formed orientation control element 501.For example resin bed can be set on glass substrate.Although to the material of resin bed without limits, can use material identical materials with any known alignment films.Perhaps, obtain imprint masters by impressing aforesaid mother matrix, imprint masters is used to form orientation control element 501 by further impressing.

(embodiment 8)

Afterwards, liquid crystal display device according to embodiment of the present invention 8 is described with reference to the accompanying drawings.

The liquid crystal display device of the present embodiment has the structure similar to the liquid crystal display device of embodiment 7.Yet in the orientation control element of the present embodiment, the normal direction of the inclined-plane 507a of each element characteristic 503 depends at substrate 502 lip-deep particular locations and tilts at different directions (different orientations).Noting, is not in the situation on plane at inclined-plane 507a, and " normal direction of inclined-plane 507a " is meant the direction perpendicular to the line 507A shown in Figure 33 C and the 33D.

Afterwards, the more detailed structure of the present embodiment orientation control element will be described.Described as reference Figure 17 A, the orientation control element of the present embodiment comprises 200 * 600 unit area (300 μ m * 100 μ m).

As shown in Figure 37 A, each unit area 574 is all halved on vertical and horizontal, thereby produces four sub regions 580.Figure 37 B is A-A ' or the B-B ' cross-sectional view of Figure 37 A.As shown in the figure, each subregion 580 all has a plurality of element characteristics 576 that are arranged in wherein.In each subregion 580, the inclined-plane 576a of element characteristic 576 has roughly the same normal direction.In each subregion, inclined-plane 576a so forms, and promptly the central plane of the unit area 574 under this subregion is outside.

With reference to Figure 37 C, will the arrangement of the element characteristic 576 in each subregion be described more specifically.Element characteristic 576 average headway Px with 1.6 μ m on perpendicular to the direction of they self ridge arranges.On the direction of these ridges, element characteristic 576 is arranged with the average headway Py of 3.2 μ m, is formed with the groove of 0.8 μ m betwixt.

In the orientation control element of the present embodiment, the normal direction on each element characteristic inclined-plane is tilting according to the predetermined direction of the particular location of the element characteristic on the substrate surface.Therefore, realized that so-called orientation cuts apart, wherein with respect to the pre-dumping direction in each presumptive area control liquid crystal layer.As a result, improved the viewing angle characteristic of liquid crystal display device.

The structure of the present embodiment orientation control element is not limited to Figure 37 A to shown in the 37C those.For example, the quantity of the size in setting unit zone 574, subregion and shape etc. arbitrarily.Be applied in the situation of display device at the orientation control element with the present embodiment, preferably each unit area 574 all has the corresponding size of each Pixel Dimensions with the display device of using described element.The size and the spacing of element characteristic 576 can be set arbitrarily.In addition, the orientation control element can have alignment films and/or conducting film in its surface.In this case, can advantageously place liquid crystal layer, to contact with alignment films.

Next, will the method that the permission of making the present embodiment is orientated the orientation control element of cutting apart be described.

At first, with the method for describing by the made orientation control element that uses the energy thermal deformation.

Method similar methods by describing to 34C with reference Figure 34 A forms wall part 526 on substrate 520, different is to arrange the resist pattern 524 that forms shown in Figure 34 B according to the element characteristic shown in Figure 37 A.

Next, as shown in Figure 34 1, form resist pattern 528 by photomask by using following mode, promptly in each subregion, described pattern with its on will form the wall part 526 on inclined-plane side 526a contact.In the present embodiment, use photomask, make respectively in upper right, upper left, the bottom right of the unit area shown in Figure 37 A or lower-left subregion, to form from upper right, upper left, the bottom right of the resist pattern 524 that is used to form wall part 526 or the move up pattern of 0.4 μ m of lower left.

Step subsequently is similar to the step of describing with reference to Figure 34 E.

Method above using, the inclined-plane that can be easy to form each all depend on ad-hoc location on substrate surface and the element characteristic of orientation in different directions.

Perhaps, can make the orientation control element of the present embodiment by following method, described method is utilized the cambial distortion based on exposure of ramp portion to similar to the method that 35E describes with reference to Figure 35 A.

At first, in the step of the formation wall part 542 as shown in Figure 35 A, arrange formation wall part 542 on substrate 540 according to the element characteristic shown in Figure 37 A.Next, the canted exposure step to negative resist layer 544 of carrying out shown in Figure 35 C and 35D as described below.At first, carry out first canted exposure by using mask, described mask has covered any part of each unit area except that upper right subregion.Similarly, carry out second, third and the 4th canted exposure by using mask, described mask has covered any part of each unit area except that bottom right, lower-left or upper left subregion.Carry out first to the 4th canted exposure with different respectively exposure directions.Afterwards, development negative resist layer 544 (Figure 35 E) has obtained the different orientation control element of the direction of orientation of its inclined-plane between different subregions thus.

Can also make the orientation control element of the present embodiment by the similar method of describing with reference Figure 36 of the method based on ink-jet technology.

At first, in the step of the formation wall part 552 shown in Figure 36 A, be arranged in formation wall part 552 on the substrate 550 according to the element characteristic shown in Figure 37.

Next, the canted exposure step shown in following execution graph 36B and the 36C to wall part 552.At first, carry out first canted exposure by using mask, described mask has covered any part of each unit area except that upper right subregion.Similarly, carry out second, third and the 4th canted exposure by using mask, described mask has covered any part of each unit area except that bottom right, lower-left or upper left subregion.Carry out first to the 4th canted exposure with different respectively exposure directions.Then, the solution that will be used to form ramp portion by ink-jet technology etc. is coated to substrate 550, afterwards with coated solution drying (Figure 36 D), has obtained the different orientation control element of the direction of orientation of its inclined-plane between different subregions thus.

Use said method, can make at an easy rate the spacing of element characteristic wherein, highly, bevel angle etc. can be arbitrarily and accurately control and the orientation control element that allows orientation to cut apart.

The orientation control element of the present embodiment can have the surface that is formed by impression.Can by with described in enforcement scheme 7 be used to form the orientation control element the method for stamping similar methods form this orientation control element.In addition, by reference Figure 34 A to 34E, Figure 35 A to 35E and the method described to 36D of 36A, can make mother matrix corresponding to for example upper right subregion, and construct four times on the surface that different zones is impressed this mother matrix, each all in different directions, the normal direction that has obtained inclined-plane wherein thus different orientation control element between different subregions.

According to the present invention, be formed on contact with liquid crystal layer lip-deep concavo-convex and given roughly pre-dumping uniformly to being positioned at along the liquid crystal molecule of vertical alignment-type liquid crystal layer thickness direction mid-plane.Can control liquid crystal aligning accurately thus.Therefore the liquid crystal display device of bright and high-contrast can be provided.By will with surface that liquid crystal layer contacts on optimize the shape, size, arrangement etc. of the element characteristic of arranging with two-dimensional array, tilt angle and pre-dumping direction can freely be set.

Because can adjust the orientation of liquid crystal layer by two-dimentional panel, so can obtain the better response characteristic than any conventional display spare, described conventional display spare utilizes its neutral line (one dimension) to apply the rib technology or the tilting electric field technology of orientation control force.

By forming heteroid element characteristic according to the particular location on the substrate surface, can realize being orientated and cut apart, make each pixel all be divided into a plurality of zones with different pre-dumping directions.In addition, the identical zone of pre-dumping direction in the single pixel can be further divided into a plurality of zones with different tilt angles.Thereby, the liquid crystal display device with outstanding viewing angle characteristic can be provided.

Have an advantage according to orientation control structure of the present invention (concavo-convex), promptly it can be by forming with high precision than making the needed easier step of any conventional orientation control assembly.

The present invention is applied to various types of vertical alignment-type liquid crystal display devices.The present invention is particularly useful for the liquid crystal display device of MVA pattern.

Although described the present invention at its embodiment preferred, should be understood that for those skilled in the art, can revise disclosed invention in every way, and can take except that above-mentioned specifically described many embodiments those.Therefore, be intended to cover all modifications of the present invention that fall in practicalness of the present invention and the scope by appended claim.

Claims (36)

1. liquid crystal display device, the electrode that comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between the described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein,

In the described a pair of substrate at least one with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure;

The surface that is formed with concaveconvex structure thereon has a zone, and the height of wherein said concaveconvex structure changes with the period 1 along first direction, and along perpendicular to the second direction of described first direction to change the second round that is different from the period 1;

Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m; And

Because described concaveconvex structure, the vertical alignment-type liquid crystal layer does not have a pre-dumping when striding across it and applying voltage.

2. liquid crystal display device according to claim 1, wherein, when striding across described vertical alignment-type liquid crystal layer and not applying voltage, be positioned at along the liquid crystal molecule of the mid-plane of described vertical alignment-type liquid crystal layer thickness direction and so be orientated, promptly the normal direction from described a pair of substrate tilts.

3. liquid crystal display device according to claim 1, the wherein said period 1 is less than described second round.

4. liquid crystal display device according to claim 1, the height of wherein said concaveconvex structure are equal to or greater than 0.2 times of described period 1.

5. liquid crystal display device according to claim 1, the height of wherein said concaveconvex structure are equal to or greater than 0.5 times of described period 1.

6. liquid crystal display device according to claim 1, wherein said concaveconvex structure comprise a plurality of element characteristics that are arranged in two-dimensional array, and each element characteristic all has asymmetric xsect along described first direction.

7. liquid crystal display device according to claim 6, wherein each element characteristic all has the xsect of general triangular along described first direction.

8. liquid crystal display device according to claim 6, wherein each element characteristic all has roughly tetragonal xsect along described first direction.

9. liquid crystal display device according to claim 8, wherein each element characteristic all has roughly trapezoidal xsect along described first direction.

10. liquid crystal display device according to claim 9, wherein a base angle of the roughly trapezoidal xsect of each element characteristic is equal to or greater than 90 ° and less than 180 °.

11. liquid crystal display device according to claim 6, wherein said element characteristic is arranged with a gap along first direction.

12. liquid crystal display device according to claim 1, wherein said concaveconvex structure comprise a plurality of grooves of arranging on second direction.

13. liquid crystal display device according to claim 12, wherein each groove part extends along described first direction.

14. liquid crystal display device according to claim 12, wherein each groove all has roughly quadrilateral and symmetrical xsect along described second direction.

15. liquid crystal display device according to claim 14, wherein each groove part has the width that is not less than 0.1 μ m and is not more than 10 μ m.

16. liquid crystal display device according to claim 6, wherein said concaveconvex structure comprises capable A and row B, each row A has the element characteristic of arranging on described first direction, each row B is identical with row A, and has moved less than the element characteristic distance of average period along described first direction; And

Row A and row B replace on described second direction.

17. a liquid crystal display device, the electrode that comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between the described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein,

In the described a pair of substrate at least one with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure;

The surface that is formed with concaveconvex structure thereon has a zone, and the height of wherein said concaveconvex structure changes with the period 1 along first direction, and changes the second round of period 1 to equal or to be different from along the second direction perpendicular to described first direction;

Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m;

Described concaveconvex structure comprises a plurality of grooves, and each groove part has the xsect of quadrilateral roughly and symmetry, and extends being different from the direction of described second direction; And

Because described concaveconvex structure, the vertical alignment-type liquid crystal layer does not have a pre-dumping when striding across it and applying voltage.

18. a liquid crystal display device, the electrode that comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between the described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein,

In the described a pair of substrate at least one with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure;

Described concaveconvex structure comprises capable A and row B, each row A has a plurality of element characteristics of arranging with the period 1 along first direction, each row B is identical with row A, and moved less than the element characteristic distance of average period along described first direction, row A and row B on perpendicular to the second direction of described first direction with the second round that equals or be different from the described period 1 alternately;

Period 1 is not less than 0.1 μ m and is not more than 10 μ m, and is not less than 0.1 μ m second round and is not more than 10 μ m; And

Because described concaveconvex structure, the vertical alignment-type liquid crystal layer does not have a pre-dumping when striding across it and applying voltage.

19. a liquid crystal display device, the electrode that comprises a pair of substrate, is arranged on the vertical alignment-type liquid crystal layer between the described a pair of substrate and is used for applying voltage to described vertical alignment-type liquid crystal layer, wherein,

In the described a pair of substrate at least one with surface that described vertical alignment-type liquid crystal layer contacts on have concaveconvex structure;

Described concaveconvex structure comprise a plurality of along first direction to be not less than 0.1 μ m and to be not more than the element characteristic of the periodic arrangement of 10 μ m, each element characteristic all has the roughly shape of column;

Each bottom surface by those the most adjacent in described a plurality of element characteristics encirclements does not all have rotation axes of symmetry on the substrate normal direction; And

Because described concaveconvex structure, the vertical alignment-type liquid crystal layer does not have a pre-dumping when striding across it and applying voltage.

20. liquid crystal display device according to claim 19, wherein, when not striding across described vertical alignment-type liquid crystal layer and apply voltage, be positioned at along the liquid crystal molecule of the mid-plane of described vertical alignment-type liquid crystal layer thickness direction and so be orientated, promptly the normal direction from described a pair of substrate tilts.

21. liquid crystal display device according to claim 19, wherein said a plurality of element characteristics have the height that is not less than 0.1 μ m and is not more than 3 μ m.

22. liquid crystal display device according to claim 19, wherein each element characteristic all is a triangular prism.

23. liquid crystal display device according to claim 19, wherein each element characteristic all is five jiaos of prisms.

24. liquid crystal display device according to claim 1, wherein each element characteristic all have according to this element characteristic on substrate ad-hoc location and definite shape.

25. liquid crystal display device according to claim 1, wherein said concaveconvex structure have constituted a plurality of subregions that cause different pre-dumping directions respectively.

26. liquid crystal display device according to claim 25, the concaveconvex structure of forming described a plurality of subregions wherein all is set on two of described a pair of substrate, makes at each subregion on of described a pair of substrate all with subregion is relative with man-to-man relation accordingly on another substrate.

27. liquid crystal display device according to claim 25, the concaveconvex structure of forming described a plurality of subregions wherein all is set on two of described a pair of substrate, makes at each subregion on of described a pair of substrate all relative with corresponding a plurality of subregions on another substrate.

28. liquid crystal display device according to claim 25 wherein only is provided with the concaveconvex structure that constitutes described a plurality of subregions on of described a pair of substrate.

29. liquid crystal display device according to claim 24 further comprises a plurality of pixels with arranged,

Wherein, in the zone corresponding to each pixel, described concaveconvex structure constitutes one group of subregion that causes different pre-dumping directions respectively.

30. liquid crystal display device according to claim 24 further comprises a plurality of pixels with arranged,

Wherein, in the zone corresponding to each pixel, described concaveconvex structure has constituted a plurality of subregion groups that cause different pre-dumping directions respectively, and described many group subregions are arranged with spacing GP.

31. liquid crystal display device according to claim 30, wherein

Each pixel all comprises the opening that allows the essentially rectangular that transmittance passes through, and described opening has along the long limit that the column direction of described picture element matrix extends with along the minor face of the line direction extension of described picture element matrix; And

Described concaveconvex structure is divided into bar constituting described a plurality of subregion, and each subregion all extends on the long limit that both is not parallel to described opening also is not parallel to the direction of its minor face.

32. liquid crystal display device according to claim 31, wherein,

The length H on the long limit of each opening _pBe substantially equal to the length W of minor face _pIntegral multiple;

The length W of minor face _pBe substantially equal to the integral multiple of the spacing GP of described subregion group; And

Described subregion extends on the direction with respect to the about 45 of described opening minor face.

33. liquid crystal display device according to claim 24, wherein each subregion all comprises a plurality of tiny areas that cause different tilt angles respectively.

34. liquid crystal display device according to claim 1, wherein said concaveconvex structure has the surface of impression.

35. a method of making the described liquid crystal display device of claim 1 comprises the steps:

Prepare the substrate that is formed with concaveconvex structure on its surface; With

Between described substrate and another substrate relative, the vertical alignment-type liquid crystal layer is set with described substrate.

36. the method for manufacturing liquid crystal display device according to claim 35, the step that wherein prepares the substrate that is formed with concaveconvex structure in its surface comprises the steps:

Preparation has the mother matrix corresponding to the surface structure of described concaveconvex structure;

The surface structure of described mother matrix is impressed on the surface of described substrate.

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